Section 2 Novel Technologies

**8**

1991

*Technological Innovation in the Olive Oil Production Chain*

Rijeka, Crotia: InTech; 2012. Available from: https://www.intechopen. com/books/olive-germplasmitalian-catalogue-of-olive-varieties/ olive-germplasm-italian-catalogue-of-

[10] Chiappetta A, Muto A, Muzzalupo R, Muzzalupo I. New rapid procedure for genetic characterization of Italian wild olive (Olea europaea) and

traceability of virgin olive oils by means of SSR markers. Scientia Horticulturae.

[11] Muzzalupo I. Breaking news on the authenticity of olive oils by means of molecular markers. Novel Techniques in Nutrition and Food Science. 2017;**1**(1):000505. Available from: https://crimsonpublishers.com/ntnf/

[12] Council for Agricultural Research and Analysis of Agricultural Economics. 2018. Available from: https://www.crea.

olive-varieties

2017;**226**(19):42-49

pdf/NTNF.000505.pdf

gov.it/it

[1] Kagermann H, Wahlster W, Helbig J, editors. Recommendations for Implementing the Strategic Initiative Industrie 4.0: Final Report of the Industries 4.0 Working Group; 2013

[2] Lasi H, Kemper HG, Fettke P, Feld T, Hoffmann M. Industry 4.0. Business & Information Systems Engineering.

[4] Ministry of the Policies Agricultural, Food, Forestry and Tourism. Report sullo stato dell'arte dell'Agricoltura di Precisione in Italia. 2015. Available from: www.politicheagricole.it

Tecnologie di Agricoltura di Precisione nella Coltivazione del Mais in una Azienda Cerealicola-Zootecnica. 2012. Available from: http://tesi.cab.unipd.

[6] Eurostat. Statistiche Sulla Struttura

[3] Egon M, Xiao-Li C, Ralph R. Challenges and requirements for the application of industry 4.0: A special insight with the usage of cyber-physical system. Chinese Journal of Mechanical Engineering. 2017;**30**(5):1050-1057

[5] Gatto S. Applicazione delle

Delle Aziende Agricole. 2015. Available from: https://ec.europa.eu/ eurostat/statistics-explained/index. php?title=Farm\_structure\_statistics/

[7] European Union Commission

Regulation. (EEC) No 2568/91. Brussels: Official European Commission Journal;

[8] International Olive Oil Council. World Olive Oil Balances for 2017/18 Market Newsletter; IOOC. 2018. Available from: ///C:/Users/alev/Downloads/ CONSOMMATION1\_ANG.pdf

[9] Muzzalupo I. Olive Germplasm— Italian Catalogue of Olive Varieties.

it/42408/

it&oldid=370120

**References**

2017;**4**(6):239-242

**11**

**Chapter 2**

**Abstract**

**1. Introduction**

*Alev Yüksel Aydar*

Emerging Extraction Technologies

In the field of olive oil extraction, current scientific research has focused on improving quality, paying particular attention to optimizing the efficiency of extraction and reducing the duration of the process. Recently, studies have been conducted to improve the traditional malaxation process and obtain positive effects on both oil production and consumption. With these aims, emerging technologies including microwave (MW), pulsed electric field (PEF), and ultrasound (US) have been applied to conventional virgin olive oil extraction process. In this chapter, most recent studies that focused on adaptation of emerging technologies to traditional extraction to increase the yield of olive oil or some minor compounds and bioactive components present in olive oil including tocopherols, chlorophyll,

in Olive Oil Production

carotenoids, and phenolic compounds have been compiled.

**Keywords:** novel technologies, olive oil, extraction, ultrasound, microwave

A flow chart of extra virgin olive oil extraction is shown in **Figure 1**.

The conventional extra virgin olive oil (EVOO) extraction method consists of three main processes, which are crushing, malaxation, and centrifugation [1]. After washing olive fruits, they are crushed using a stone-mill, hammers, disc crushers, de-stoning machines, or blades [2]. The purpose of this step is to facilitate the release of the oil droplets from the Elaioplasts. The minimum size for the continuous separation process of olive oil is 30 μm, but only 45% of the oil droplets have a diameter greater than 30 μm after crushing increases. This ratio reaches 80% with the formation of larger diameter drops from the oil droplets by malaxation [3]. Malaxation and crushing are main steps that affect the quality and yield of oil [4].

Conventional techniques in olive oil extraction have not changed significantly for last 20 years [5]. However, in line with research findings and new techniques developed by market demand, the ongoing food industry has become very active in looking for new methods for food innovation. But, it is still very uncommon for the food industry to develop and adopt advanced processing techniques in the direction of consumers' increasing food safety and quality requirements [6]. Researchers working on the development of food technology are making great efforts to develop and implement "minimal processing" strategies to remove the negative effects of traditional food processing methods. The most general definition of minimal processing can be: preserving the nutritional quality and sensory qualities of food by heat application, which is the basic protection step in food processing, for a shorter

#### **Chapter 2**

## Emerging Extraction Technologies in Olive Oil Production

*Alev Yüksel Aydar*

#### **Abstract**

In the field of olive oil extraction, current scientific research has focused on improving quality, paying particular attention to optimizing the efficiency of extraction and reducing the duration of the process. Recently, studies have been conducted to improve the traditional malaxation process and obtain positive effects on both oil production and consumption. With these aims, emerging technologies including microwave (MW), pulsed electric field (PEF), and ultrasound (US) have been applied to conventional virgin olive oil extraction process. In this chapter, most recent studies that focused on adaptation of emerging technologies to traditional extraction to increase the yield of olive oil or some minor compounds and bioactive components present in olive oil including tocopherols, chlorophyll, carotenoids, and phenolic compounds have been compiled.

**Keywords:** novel technologies, olive oil, extraction, ultrasound, microwave

#### **1. Introduction**

The conventional extra virgin olive oil (EVOO) extraction method consists of three main processes, which are crushing, malaxation, and centrifugation [1]. After washing olive fruits, they are crushed using a stone-mill, hammers, disc crushers, de-stoning machines, or blades [2]. The purpose of this step is to facilitate the release of the oil droplets from the Elaioplasts. The minimum size for the continuous separation process of olive oil is 30 μm, but only 45% of the oil droplets have a diameter greater than 30 μm after crushing increases. This ratio reaches 80% with the formation of larger diameter drops from the oil droplets by malaxation [3]. Malaxation and crushing are main steps that affect the quality and yield of oil [4]. A flow chart of extra virgin olive oil extraction is shown in **Figure 1**.

Conventional techniques in olive oil extraction have not changed significantly for last 20 years [5]. However, in line with research findings and new techniques developed by market demand, the ongoing food industry has become very active in looking for new methods for food innovation. But, it is still very uncommon for the food industry to develop and adopt advanced processing techniques in the direction of consumers' increasing food safety and quality requirements [6]. Researchers working on the development of food technology are making great efforts to develop and implement "minimal processing" strategies to remove the negative effects of traditional food processing methods. The most general definition of minimal processing can be: preserving the nutritional quality and sensory qualities of food by heat application, which is the basic protection step in food processing, for a shorter

**Figure 1.** *Flow chart of olive oil extraction.*

period of time. [7]. Emerging technologies including microwave, high-pressure processing, pulsed light, radio frequency, Ohmic heating, ultrasound, and pulsed electric field (PEF) are widely applied emerging minimal processes in the food industry.

In recent years, novel technologies such as ultrasound, pulsed electric field, or microwave have been adopted in olive oil extraction [1, 8–10] because of their positive effects including enhanced extraction efficiency, reduced extraction time, increased yield, and low energy consumption.

Ultrasound is one of the main emerging technologies widely used in various extraction processes of plant materials [11, 12]. In order to enhance oil extraction, ultrasound can be applied to the olive paste due to its mechanic effect on the cell membranes, which induces them to release oil easily from vacuoles with a considerably lower malaxation time and higher oil quality and yield [2, 5, 10, 13–18]. In addition to the extraction process, ultrasound was also investigated in numerous studies on food processing methods including emulsification, filtration, crystallization, inactivation of enzymes and microorganisms, thawing, and freezing on foods [19, 20].

It has been demonstrated that pulsed electric field (PEF), another non-thermal technology, is effective for reversible or irreversible permeabilization of cell membranes in several plant tissues, without significant temperature increase [8]. PEF technology, which has been used in the field of food science since 1960, is based on the principle of exposing liquid or solid food products to an electric field causing pores in cell membranes [6].

Microwave-assisted extraction (MAE) is an alternative oil extraction method in recent years. Since microwave provides more rapid heating and destruction of biological cell structures in a shorter time, it is a more efficient extraction method than

**13**

Unspecified/Olive pomace used

*Emerging Extraction Technologies in Olive Oil Production*

environmental impact and financial costs [21].

conventional processes. Other important advantages of this method are obtaining high-quality oil and low energy requirement, which cause a significant reduction in

More emphasis has been placed on the understanding of a superior EVOO quality based on the preservation of the sensory characteristics and positive health properties of olive oil in recent years. This aspect of EVOO quality is strongly related to the presence of phenolic and volatile compounds [13, 22]. Therefore, utilization of an emerging technology in olive oil extraction should not only increase oil yield, but also protect and improve the bioactive oil compounds and the oil quality. Recent studies that applied emerging technologies to olive oil extraction are sum-

> **Investigated parameters**

time, ultrasound temperature, malaxation time

application step (After crushing/ before crushing)

application of ultrasound

ultrasound application before centrifugation

malaxation time

HPU intensity, fruit temperature, olive moisture, and fat content

US and MW

and temperature, electric field strength (kV/cm)

irradiation time, solvent-to-sample

Arroniz PEF Application of PEF Oil yield, acidity,

MW Microwave power,

ratio

**Dependent variables Refs.**

Olive paste temperature [15]

Olive paste temperature [25]

[1]

[10]

[23]

[24]

[14]

[8]

[9]

[26]

Oil yield, acidity, peroxide value, and antioxidant properties

Olive paste temperature, energy balance, oil yield, quality indices of oil, minor compounds

Oil yield, quality indices, volatile and minor compounds, fatty acid composition

Oil yield, UV absorbance values acidity, peroxide value, total phenolic content

Malaxation time, oil yield, quality characteristics, and energy efficiency

Oil yield, acidity, quality characteristics, total and individual

quality characteristics, total phenols, sensory

phenols

properties

Oil yield, physicochemical oil properties

*DOI: http://dx.doi.org/10.5772/intechopen.81390*

marized in **Table 1**.

**Variety of olive Emerging** 

**technology\***

Edremit HPU Ultrasound

Coratina HPU Ultrasound

Picual HPU Direct/indirect

Picual HPU Continuous

Edremit, Gemlik, Uslu HPU Ultrasound and

Picual HPU Olive paste flow,

Ogliarola Barese HPU, MW Thermal effect of

Arbequina PEF Malaxation time

*Technological Innovation in the Olive Oil Production Chain*

period of time. [7]. Emerging technologies including microwave, high-pressure processing, pulsed light, radio frequency, Ohmic heating, ultrasound, and pulsed electric field (PEF) are widely applied emerging minimal processes in the food

In recent years, novel technologies such as ultrasound, pulsed electric field, or microwave have been adopted in olive oil extraction [1, 8–10] because of their positive effects including enhanced extraction efficiency, reduced extraction time,

Ultrasound is one of the main emerging technologies widely used in various extraction processes of plant materials [11, 12]. In order to enhance oil extraction, ultrasound can be applied to the olive paste due to its mechanic effect on the cell membranes, which induces them to release oil easily from vacuoles with a considerably lower malaxation time and higher oil quality and yield [2, 5, 10, 13–18]. In addition to the extraction process, ultrasound was also investigated in numerous studies on food processing methods including emulsification, filtration, crystallization, inactivation of enzymes and microorganisms, thawing, and freezing on foods

It has been demonstrated that pulsed electric field (PEF), another non-thermal technology, is effective for reversible or irreversible permeabilization of cell membranes in several plant tissues, without significant temperature increase [8]. PEF technology, which has been used in the field of food science since 1960, is based on the principle of exposing liquid or solid food products to an electric field causing

Microwave-assisted extraction (MAE) is an alternative oil extraction method in recent years. Since microwave provides more rapid heating and destruction of biological cell structures in a shorter time, it is a more efficient extraction method than

increased yield, and low energy consumption.

**12**

industry.

**Figure 1.**

*Flow chart of olive oil extraction.*

[19, 20].

pores in cell membranes [6].

conventional processes. Other important advantages of this method are obtaining high-quality oil and low energy requirement, which cause a significant reduction in environmental impact and financial costs [21].

More emphasis has been placed on the understanding of a superior EVOO quality based on the preservation of the sensory characteristics and positive health properties of olive oil in recent years. This aspect of EVOO quality is strongly related to the presence of phenolic and volatile compounds [13, 22]. Therefore, utilization of an emerging technology in olive oil extraction should not only increase oil yield, but also protect and improve the bioactive oil compounds and the oil quality. Recent studies that applied emerging technologies to olive oil extraction are summarized in **Table 1**.



#### **Table 1.**

*Emerging extraction technologies used in olive oil production.*

#### **2. Ultrasound applications in olive oil extraction**

In the olive oil industry, ultrasound is the one of the most promising technologies because of its powerful mechanical and mild thermal effects [32]. Many researchers have used this technology to investigate its effects on overall olive oil quality and yield in the last decade [1, 10, 14–16, 23–25, 33]. In recent years, it has been discovered that using a stronger ultrasound (>1 W/cm2 ) at a lower frequency (generally around 20–50 kHz), which is also called high-power ultrasound (HPU) (usually around 20–50 kHz), is physically effective in altering the properties of a substance or inactivating microorganisms [6, 7].

High-power ultrasound application in olive oil extraction was first performed by Jiménez et al. [15] under discontinuous conditions. In their studies investigating the effects of direct and indirect ultrasound, they found that direct sonication provided better extractability in high-moisture olives (>50%) while greater extractability was obtained by indirect sonication in low-moisture olive fruits (<50%) [15].

Enrichment of olive oil with main phenols in olive leaves using ultrasound has been studied by researchers [34, 35]. Achat et al. [34] used ultrasound to enrich olive oil with oleuropein both on a laboratory and a pilot plant scale. The ultrasound-assisted extraction method greatly facilitated the enrichment of VOO in phenolic compounds compared to conventional processes. They found that tyrosol and hydroxytyrosol, main phenolic compounds present in olive oil, were not significantly degraded by sonication [34].

Clodoveo et al. [10] investigated ultrasound application on olive fruits submerged in a water bath before crushing and also on olive paste after crushing. The purpose of their study was to test the possibility of decreasing the malaxation time. Reduction in the malaxation time and improvement in oil yields and its minor nutritional compounds were attained by ultrasound technology. The results were better in oils obtained by sonication of olives in water bath than those obtained by sonication of olive paste [10].

Bejaoui et al. [25] applied HPU to olive paste through the pipe before centrifugation with continuous conditions. They observed that when the oils were extracted

**15**

*Emerging Extraction Technologies in Olive Oil Production*

cant effect (p > 0.05) on the acidity and yield [36].

**3. PEF applications in olive oil extraction**

than the control group. [9]

without ultrasound, the extraction yield was 46.83% ± 0.83, while ultrasound treatment of olive paste produced a significant increase in extraction yields to

Aydar et al. [1] used an ultrasound bath in olive oil extraction to find optimum ultrasound-assisted olive oil extraction conditions based on maximum oil yield and minimum free acidity. The acidity of the oils for all experiments was below the legal limit (<8 g oleic acid/kg oil) established for the category of EVOO [36]. The most important impact on the extraction yield and the acidity (p < 0.05) was due to the malaxation temperature. They also observed that ultrasound time had no signifi-

The effect of malaxation time combined with the use of ultrasound on the oil yield, oxidative and quality characteristics of EVOOs extracted from different Turkish olive cultivars was studied by Aydar [24]. It was found that different sonication and malaxation time combinations did not cause difference (p > 0.05) in the Edremit oil yield and extractability indexes, while they were significantly different in Uslu and Gemlik oils. In that study, oils obtained by 8 min of ultrasound application and 22 min of malaxa-

Olive paste was exposed to PEF technology involving 50 monopolar pulses of 3 μs at an electric field strength of 1 kV/cm (1.47 kJ/kg) and 2 kV/cm (5.22 kJ/kg) and a frequency of 125 Hz. PEF did not result in any significant differences in fatty acid composition and sensorial properties of oil. In sensorial properties point, panelists evaluated the oil subjected to PEF was less bitter and pungent, and more fruity than the untreated oils. The PEF treatment was very effective to increase the oil yield when combined with malaxation. The oil yield as was high as 14.10% when the olive paste was subjected to PEF at 2 kV/cm and malaxated for 30 min at 15°C. However, the extraction yield was reduced by 50% when no malaxation was

Effect of the use of pulsed electric field (PEF) technology on Arroniz olive oil production in terms of extraction yield and chemical and sensory quality has been evaluated by Puértolas and Marañón [9]. Extraction yield increased by 13.3% in PEF-treated samples (2 kV/cm, 11.25 kJ/kg) compared to control. In addition, the total phenolic content, total phytosterol, and total tocopherol of olive oil extracted with PEF showed significantly higher values (11.5, 9.9, and 15.0%, respectively)

Over the last few decades, microwave treatments in food processing have gained popularity because of their low heat treatment times, operational simplicity, and high heating rates, which result in lower maintenance requirements. The microwaves obtained from household ovens and many industrial applications are

The effect of heating with microwave and its comparison with conventional heating and ultrasound heating on crushed olives was investigated by Clodoveo and Hbaieb [14]. Results showed that the main quality parameters legally established (acidity, peroxide value, and specific extinction coefficients (K232 and K270)) to evaluate VOO were not affected by the microwave and ultrasound treatments. Moreover, the malaxation time was decreased and extraction yield was improved by

produced efficiently by permanent wave magnetrons (**Figure 2**) [6].

tion had highest oil yield and chlorophyll and carotenoid contents. [24].

applied to olive paste compared to those malaxated for 30 min. [8]

**4. Microwave applications in olive oil extraction**

*DOI: http://dx.doi.org/10.5772/intechopen.81390*

52.75% ± 1.39.

*Emerging Extraction Technologies in Olive Oil Production DOI: http://dx.doi.org/10.5772/intechopen.81390*

*Technological Innovation in the Olive Oil Production Chain*

**technology\***

Chemlal MW The extraction

Coratina MW/MS MW and MS

Peranzana MW Malaxation time

**Variety of olive Emerging** 

Unspecified/Olive oil

used

**Table 1.**

**2. Ultrasound applications in olive oil extraction**

*Emerging extraction technologies used in olive oil production.*

been discovered that using a stronger ultrasound (>1 W/cm2

substance or inactivating microorganisms [6, 7].

cantly degraded by sonication [34].

In the olive oil industry, ultrasound is the one of the most promising technolo-

**Investigated parameters**

time, acetic acid content in hexane, irradiation power

combined effect

and MW

MW Microwave heating times

Coratina HPU Sonication time Oil yield, oil quality

*\*HPU: High-power ultrasound, PEF: Pulsed electric field, MS: Megasonic treatment, MW: Microwave.*

(generally around 20–50 kHz), which is also called high-power ultrasound (HPU) (usually around 20–50 kHz), is physically effective in altering the properties of a

High-power ultrasound application in olive oil extraction was first performed by Jiménez et al. [15] under discontinuous conditions. In their studies investigating the effects of direct and indirect ultrasound, they found that direct sonication provided better extractability in high-moisture olives (>50%) while greater extractability was

Clodoveo et al. [10] investigated ultrasound application on olive fruits submerged in a water bath before crushing and also on olive paste after crushing. The purpose of their study was to test the possibility of decreasing the malaxation time. Reduction in the malaxation time and improvement in oil yields and its minor nutritional compounds were attained by ultrasound technology. The results were better in oils obtained by sonication of olives in water bath than those obtained by sonication of olive paste [10]. Bejaoui et al. [25] applied HPU to olive paste through the pipe before centrifugation with continuous conditions. They observed that when the oils were extracted

) at a lower frequency

**Dependent variables Refs.**

[27]

[28]

[29]

[30]

[31]

Oil yield, total phenols, quality parameters

Rheological properties,

Energy consumption, oil yield, structure modifications of olive

indices, phenolic composition

Quality and physicochemical properties, oil color

oil yield

pastes

gies because of its powerful mechanical and mild thermal effects [32]. Many researchers have used this technology to investigate its effects on overall olive oil quality and yield in the last decade [1, 10, 14–16, 23–25, 33]. In recent years, it has

obtained by indirect sonication in low-moisture olive fruits (<50%) [15].

Enrichment of olive oil with main phenols in olive leaves using ultrasound has been studied by researchers [34, 35]. Achat et al. [34] used ultrasound to enrich olive oil with oleuropein both on a laboratory and a pilot plant scale. The ultrasound-assisted extraction method greatly facilitated the enrichment of VOO in phenolic compounds compared to conventional processes. They found that tyrosol and hydroxytyrosol, main phenolic compounds present in olive oil, were not signifi-

**14**

without ultrasound, the extraction yield was 46.83% ± 0.83, while ultrasound treatment of olive paste produced a significant increase in extraction yields to 52.75% ± 1.39.

Aydar et al. [1] used an ultrasound bath in olive oil extraction to find optimum ultrasound-assisted olive oil extraction conditions based on maximum oil yield and minimum free acidity. The acidity of the oils for all experiments was below the legal limit (<8 g oleic acid/kg oil) established for the category of EVOO [36]. The most important impact on the extraction yield and the acidity (p < 0.05) was due to the malaxation temperature. They also observed that ultrasound time had no significant effect (p > 0.05) on the acidity and yield [36].

The effect of malaxation time combined with the use of ultrasound on the oil yield, oxidative and quality characteristics of EVOOs extracted from different Turkish olive cultivars was studied by Aydar [24]. It was found that different sonication and malaxation time combinations did not cause difference (p > 0.05) in the Edremit oil yield and extractability indexes, while they were significantly different in Uslu and Gemlik oils. In that study, oils obtained by 8 min of ultrasound application and 22 min of malaxation had highest oil yield and chlorophyll and carotenoid contents. [24].

#### **3. PEF applications in olive oil extraction**

Olive paste was exposed to PEF technology involving 50 monopolar pulses of 3 μs at an electric field strength of 1 kV/cm (1.47 kJ/kg) and 2 kV/cm (5.22 kJ/kg) and a frequency of 125 Hz. PEF did not result in any significant differences in fatty acid composition and sensorial properties of oil. In sensorial properties point, panelists evaluated the oil subjected to PEF was less bitter and pungent, and more fruity than the untreated oils. The PEF treatment was very effective to increase the oil yield when combined with malaxation. The oil yield as was high as 14.10% when the olive paste was subjected to PEF at 2 kV/cm and malaxated for 30 min at 15°C. However, the extraction yield was reduced by 50% when no malaxation was applied to olive paste compared to those malaxated for 30 min. [8]

Effect of the use of pulsed electric field (PEF) technology on Arroniz olive oil production in terms of extraction yield and chemical and sensory quality has been evaluated by Puértolas and Marañón [9]. Extraction yield increased by 13.3% in PEF-treated samples (2 kV/cm, 11.25 kJ/kg) compared to control. In addition, the total phenolic content, total phytosterol, and total tocopherol of olive oil extracted with PEF showed significantly higher values (11.5, 9.9, and 15.0%, respectively) than the control group. [9]

#### **4. Microwave applications in olive oil extraction**

Over the last few decades, microwave treatments in food processing have gained popularity because of their low heat treatment times, operational simplicity, and high heating rates, which result in lower maintenance requirements. The microwaves obtained from household ovens and many industrial applications are produced efficiently by permanent wave magnetrons (**Figure 2**) [6].

The effect of heating with microwave and its comparison with conventional heating and ultrasound heating on crushed olives was investigated by Clodoveo and Hbaieb [14]. Results showed that the main quality parameters legally established (acidity, peroxide value, and specific extinction coefficients (K232 and K270)) to evaluate VOO were not affected by the microwave and ultrasound treatments. Moreover, the malaxation time was decreased and extraction yield was improved by

**Figure 2.** *Microwave oven parts.*

ultrasound and microwave treatments compared with the oils that were extracted from the olive paste without malaxation. [14].

Yanık et al. investigated microwave-assisted solvent extraction (MASE) parameters on olive pomace oil. The yield of oil obtained by conventional extraction was lower than that of oil obtained by microwave extraction from olive pomace. It demonstrated that microwave-extracted oils had higher total phenolic (985 mg caffeic acid/kg oil) and tocopherol compounds (278.07 mg/kg oil), also lower peroxide value (17.8 meq O2/kg oil) and polycyclic aromatic hydrocarbons (PAH) (0.44 μg benzo(α) pyrene/kg) compared to oils extracted by conventional industrial methods. [26]

The effect of microwave-assisted solvent extraction at two different radiation power values (170 and 510 W) combined with acetic acid on yield and physicochemical properties of olive oil was studied by Kadi et al. [27]. The UV absorbance values were highest in oils treated with 510-W microwave and 7.5% acetic acid content. Since microwave radiations accelerate the disruption of cells and oil release, they observed similar results to those of previous researchers who also achieved better oil extractability [27].

Malheiro et al. determined the effect of different microwave heating times (1, 3, 5, 10, and 15 min) on three Portuguese olive oils of different origins, one from the north, "Azeite de Trás-os-Montes" protected designation of origin (PDO); one from the center, "Azeites da Beira Interior" PDO; and one from the south of Portugal, "Azeite de Moura". They evaluated the effect of MW time on free acidity; peroxide value (PV); specific extinction coefficients (K232 and K270); color; and chlorophyll, carotenoid, and tocopherol content of oils. The carotenoids and chlorophyll pigments, which are also significant in determining olive oil stability, decreased by microwave treatment [28].

Leone et al. [30] determined the effect of microwave treatment on oil yield, structure modifications of olive pastes, and total energy consumption for a whole extraction process. The oil extractability was not significantly different from traditional extraction; however, the electrical power consumption using a microwave prototype system was higher by 24% [30].

The possibility of combining megasonic and microwave treatment in a continuous olive oil extraction system to enhance olive oil extractability was examined by Leone et al. [29]. The utilization of combined megasonic and microwave treatment to olive paste resulted in a consistent reduction of viscosity. In result, both microwave and megasonic technologies have improved the oil extractability performance by lowering the consistency of the olive paste [29].

In recent years, infrared spectroscopy, computer vision, machine olfaction technology, electronic tongues, and dielectric spectroscopy are some of the main

**17**

provided the original work is properly cited.

*Emerging Extraction Technologies in Olive Oil Production*

these new technologies and to ensure their advantages.

The author declares that she has no "conflict of interest."

sensing technologies applied to the virgin olive oil production process. Infrared spectroscopy can also be used to evaluate the official quality parameters of olive

Worldwide, the total consumption of olive oil increased from 1,666,500 tons in 1990/1991 to 2,978,000 tons in the period of 2017/2018 after 27 years [30]. Recent studies on emerging extraction techniques aim to improve the quality and physicochemical properties of oils and reduce the processing time and energy consumed during extraction compared to traditional methods. Ultrasound, microwave, and pulsed electric field technologies have been successfully applied to olive oil extraction, and several positive impacts on oil yield and quality have been observed. Results show combining these emerging technologies could assist in the development of a continuous olive oil extraction process with a higher extractability than the traditional batch process without significant decrease in oil quality. Long-term stability and sensory studies should also be done to evaluate the long-term effects of

*DOI: http://dx.doi.org/10.5772/intechopen.81390*

fruits and oil [37]**.**

**5. Conclusions**

**Conflict of interest**

**Author details**

Alev Yüksel Aydar

University, Manisa, Turkey

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

Department of Food Engineering, Faculty of Engineering, Manisa Celal Bayar

\*Address all correspondence to: alevyuksel.aydar@cbu.edu.tr

sensing technologies applied to the virgin olive oil production process. Infrared spectroscopy can also be used to evaluate the official quality parameters of olive fruits and oil [37]**.**

#### **5. Conclusions**

*Technological Innovation in the Olive Oil Production Chain*

from the olive paste without malaxation. [14].

better oil extractability [27].

**Figure 2.**

*Microwave oven parts.*

microwave treatment [28].

prototype system was higher by 24% [30].

by lowering the consistency of the olive paste [29].

ultrasound and microwave treatments compared with the oils that were extracted

eters on olive pomace oil. The yield of oil obtained by conventional extraction was lower than that of oil obtained by microwave extraction from olive pomace. It demonstrated that microwave-extracted oils had higher total phenolic (985 mg caffeic acid/kg oil) and tocopherol compounds (278.07 mg/kg oil), also lower peroxide value (17.8 meq O2/kg oil) and polycyclic aromatic hydrocarbons (PAH) (0.44 μg benzo(α) pyrene/kg) compared to oils extracted by conventional industrial methods. [26] The effect of microwave-assisted solvent extraction at two different radiation power values (170 and 510 W) combined with acetic acid on yield and physicochemical properties of olive oil was studied by Kadi et al. [27]. The UV absorbance values were highest in oils treated with 510-W microwave and 7.5% acetic acid content. Since microwave radiations accelerate the disruption of cells and oil release, they observed similar results to those of previous researchers who also achieved

Yanık et al. investigated microwave-assisted solvent extraction (MASE) param-

Malheiro et al. determined the effect of different microwave heating times (1, 3, 5, 10, and 15 min) on three Portuguese olive oils of different origins, one from the north, "Azeite de Trás-os-Montes" protected designation of origin (PDO); one from the center, "Azeites da Beira Interior" PDO; and one from the south of Portugal, "Azeite de Moura". They evaluated the effect of MW time on free acidity; peroxide value (PV); specific extinction coefficients (K232 and K270); color; and chlorophyll, carotenoid, and tocopherol content of oils. The carotenoids and chlorophyll pigments, which are also significant in determining olive oil stability, decreased by

Leone et al. [30] determined the effect of microwave treatment on oil yield, structure modifications of olive pastes, and total energy consumption for a whole extraction process. The oil extractability was not significantly different from traditional extraction; however, the electrical power consumption using a microwave

The possibility of combining megasonic and microwave treatment in a continuous olive oil extraction system to enhance olive oil extractability was examined by Leone et al. [29]. The utilization of combined megasonic and microwave treatment to olive paste resulted in a consistent reduction of viscosity. In result, both microwave and megasonic technologies have improved the oil extractability performance

In recent years, infrared spectroscopy, computer vision, machine olfaction technology, electronic tongues, and dielectric spectroscopy are some of the main

**16**

Worldwide, the total consumption of olive oil increased from 1,666,500 tons in 1990/1991 to 2,978,000 tons in the period of 2017/2018 after 27 years [30]. Recent studies on emerging extraction techniques aim to improve the quality and physicochemical properties of oils and reduce the processing time and energy consumed during extraction compared to traditional methods. Ultrasound, microwave, and pulsed electric field technologies have been successfully applied to olive oil extraction, and several positive impacts on oil yield and quality have been observed. Results show combining these emerging technologies could assist in the development of a continuous olive oil extraction process with a higher extractability than the traditional batch process without significant decrease in oil quality. Long-term stability and sensory studies should also be done to evaluate the long-term effects of these new technologies and to ensure their advantages.

#### **Conflict of interest**

The author declares that she has no "conflict of interest."

#### **Author details**

Alev Yüksel Aydar Department of Food Engineering, Faculty of Engineering, Manisa Celal Bayar University, Manisa, Turkey

\*Address all correspondence to: alevyuksel.aydar@cbu.edu.tr

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

### **References**

[1] Aydar AY, Bagdatlioglu N, Köseoglu O. Effect of ultrasound on olive oil extraction and optimization of ultrasound-assisted extraction of extra virgin olive oil by response surface methodology (RSM). Grasas y Aceites. 2017;**68**:1-11 [Epub ahead of print]. DOI: 10.3989/gya.1057162

[2] Veneziani G, Sordini B, Taticchi A, Esposto S, Selvaggini R, Urbani S, Di Maio I, Servili M. Improvement of Olive Oil Mechanical Extraction: New Technologies, Process Efficiency, and Extra Virgin Olive Oil Quality. Products from Olive Tree Dimitrios Boskou and Maria Lisa Clodoveo. IntechOpen. 2016. DOI: 10.5772/64796. Available from: https://www.intechopen.com/ books/products-from-olive-tree/ improvement-of-olive-oil-mechanicalextraction-new-technologies-processefficiency-and-extra-virgin

[3] Boskou D. Olive oil, Chemistry and Technology. Thessaloniki, Greece: AOCS; 2006. [Epub ahead of print]. DOI: 10.1159/000097916

[4] Clodoveo ML, Hbaieb RH, Kotti F, et al. Mechanical strategies to increase nutritional and sensory quality of virgin olive oil by modulating the endogenous enzyme activities. Comprehensive Reviews in Food Science and Food Safety. 2014;**13**:135-154

[5] Clodoveo ML. An overview of emerging techniques in virgin olive oil extraction process: Strategies in the development of innovative plants. Journal of Agricultural Engineering. 2013;**44**:49-59 [Epub ahead of print]. DOI: 10.4081/jae.2013.s2.e60

[6] Sun D-W. Emerging Technologies for Food Processing. 2nd ed. Dublin: Elsevier Inc.; 2014

[7] Baysal T, İçier F. Gıda Mühendİslİğİnde Isıl Olmayan Teknolojİler. Bornova, İzmir: Nobel yayıncılık; 2012

[8] Abenoza M, Benito M, Saldaña G, et al. Effects of pulsed electric field on yield extraction and quality of olive oil. Food and Bioprocess Technology. 2013;**6**:1367-1373

[9] Puértolas E, Martínez de Marañón I. Olive oil pilot-production assisted by pulsed electric field: Impact on extraction yield, chemical parameters and sensory properties. Food Chemistry. 2015;**167**:497-502

[10] Clodoveo ML, Durante V, La Notte D. Working towards the development of innovative ultrasound equipment for the extraction of virgin olive oil. Ultrasonics Sonochemistry. 2013;**20**:1261-1270

[11] Aydar AY. Utilization of Response Surface Methodology in Optimization of Extraction of Plant Materials. United Kingdom: Intech Open; 2018. pp. 157-169

[12] Amirante R, Distaso E, Tamburrano P, et al. Acoustic cavitation by means ultrasounds in the extra virgin olive oil extraction process. Energy Procedia. 2017;**126**:82-90

[13] Clodoveo ML. New advances in the development of innovative virgin olive oil extraction plants: Looking back to see the future. Food Research International. 2013;**54**:726-729

[14] Clodoveo ML, Hachicha Hbaieb R. Beyond the traditional virgin olive oil extraction systems: Searching innovative and sustainable plant engineering solutions. Food Research International. 2013;**54**:1926-1933

[15] Jiménez A, Beltrán G, Uceda M. High-power ultrasound in olive paste pretreatment. Effect on process yield and virgin olive oil characteristics. Ultrasonics Sonochemistry. 2007;**14**:725-731

**19**

*Emerging Extraction Technologies in Olive Oil Production*

malaxation, a laboratory scale approach: Effect on virgin olive oil quality criteria and yield. European Journal of Lipid Science and Technology. 2016;**118**:332- 336. [Epub ahead of print]. DOI:

10.1002/ejlt.201500020

2016;**69**:175-184

2017;**77**:45-51

2009;**47**:92-97

2017;**42**:56-63

[24] Aydar AY. Physicochemical characteristics of extra virgin olive oils obtained by ultrasound assisted extraction from different olive cultivars. International Journal of Scientific and Technology Research. 2018;**4**:1-10

[25] Bejaoui MA, Beltran G, Aguilera MP, et al. Continuous conditioning of olive paste by high power ultrasounds: Response surface methodology to predict temperature and its effect on oil yield and virgin olive oil characteristics. LWT - Food Science and Technology.

[26] Yanık DK. Alternative to traditional olive pomace oil extraction systems: Microwave-assisted solvent extraction of oil from wet olive pomace. LWT - Food Science and Technology.

[27] Kadi H, Moussaoui R, Djadoun S, et al. Microwave assisted extraction of olive oil pomace by acidic hexane. Iranian journal of chemistry and chemical engineering. 2016;**35**:73-79

[28] Malheiro R, Oliveira I, Vilas-Boas M, et al. Effect of microwave heating with different exposure times on physical and chemical parameters of olive oil. Food and Chemical Toxicology.

[29] Leone A, Romaniello R, Tamborrino A, et al. Microwave and megasonics combined technology for a continuous olive oil process with enhanced extractability. Innovative Food Science and Emerging Technologies.

[30] Leone A, Tamborrino A, Zagaria R, et al. Plant innovation in the olive

*DOI: http://dx.doi.org/10.5772/intechopen.81390*

[16] Clodoveo ML, Durante V, La Notte D, et al. Ultrasound-assisted extraction of virgin olive oil to improve the process efficiency. European Journal of Lipid Science and Technology.

2013;**115**:1062-1069

[17] Clodoveo ML, Camposeo S, Amirante R, et al. Research and Innovative Approaches to Obtain Virgin Olive Oils with a Higher Level of Bioactive Constituents. AOCS Press. 2015. [Epub ahead of print]. DOI: 10.1016/ B978-1-63067-041-2.50013-6

[18] Clodoveo ML, Dipalmo T, Schiano C, et al. What's now, what's new and what's next in virgin olive oil elaboration systems? A perspective on current knowledge and future trends. Journal of Agricultural Engineering. 2014;**45**:49

[19] Bermúdez-aguirre D, Mobbs T, Barbosa-cánovas GV. Ultrasound Technologies for Food and Bioprocessing. Springer. 2011. [Epub ahead of print]. DOI: 10.1007/978-1-4419-7472-3

[20] Chemat F, Zill-E-Huma R, Khan MK. Applications of ultrasound in food technology: Processing,

Sonochemistry. 2011;**18**:813-835

preservation and extraction. Ultrasonics

[21] Çavdar HK, Yanık DK, Gök U, et al. Optimisation of microwave-assisted extraction of pomegranate (*Punica granatum* L.) seed oil and evaluation of Its physicochemical and bioactive properties. Food Technology and Biotechnology. 2017;**55**:86-94

[22] Taticchi A, Esposto S, Veneziani G, et al. The influence of the malaxation temperature on the activity of

polyphenoloxidase and peroxidase and on the phenolic composition of virgin olive oil. Food Chemistry. 2013;**136**:975-983

[23] Bejaoui MA, Beltrán G, Sánchez-Ortiz A, et al. Continuous high power ultrasound treatment before

*Emerging Extraction Technologies in Olive Oil Production DOI: http://dx.doi.org/10.5772/intechopen.81390*

[16] Clodoveo ML, Durante V, La Notte D, et al. Ultrasound-assisted extraction of virgin olive oil to improve the process efficiency. European Journal of Lipid Science and Technology. 2013;**115**:1062-1069

[17] Clodoveo ML, Camposeo S, Amirante R, et al. Research and Innovative Approaches to Obtain Virgin Olive Oils with a Higher Level of Bioactive Constituents. AOCS Press. 2015. [Epub ahead of print]. DOI: 10.1016/ B978-1-63067-041-2.50013-6

[18] Clodoveo ML, Dipalmo T, Schiano C, et al. What's now, what's new and what's next in virgin olive oil elaboration systems? A perspective on current knowledge and future trends. Journal of Agricultural Engineering. 2014;**45**:49

[19] Bermúdez-aguirre D, Mobbs T, Barbosa-cánovas GV. Ultrasound Technologies for Food and Bioprocessing. Springer. 2011. [Epub ahead of print]. DOI: 10.1007/978-1-4419-7472-3

[20] Chemat F, Zill-E-Huma R, Khan MK. Applications of ultrasound in food technology: Processing, preservation and extraction. Ultrasonics Sonochemistry. 2011;**18**:813-835

[21] Çavdar HK, Yanık DK, Gök U, et al. Optimisation of microwave-assisted extraction of pomegranate (*Punica granatum* L.) seed oil and evaluation of Its physicochemical and bioactive properties. Food Technology and Biotechnology. 2017;**55**:86-94

[22] Taticchi A, Esposto S, Veneziani G, et al. The influence of the malaxation temperature on the activity of polyphenoloxidase and peroxidase and on the phenolic composition of virgin olive oil. Food Chemistry. 2013;**136**:975-983

[23] Bejaoui MA, Beltrán G, Sánchez-Ortiz A, et al. Continuous high power ultrasound treatment before

malaxation, a laboratory scale approach: Effect on virgin olive oil quality criteria and yield. European Journal of Lipid Science and Technology. 2016;**118**:332- 336. [Epub ahead of print]. DOI: 10.1002/ejlt.201500020

[24] Aydar AY. Physicochemical characteristics of extra virgin olive oils obtained by ultrasound assisted extraction from different olive cultivars. International Journal of Scientific and Technology Research. 2018;**4**:1-10

[25] Bejaoui MA, Beltran G, Aguilera MP, et al. Continuous conditioning of olive paste by high power ultrasounds: Response surface methodology to predict temperature and its effect on oil yield and virgin olive oil characteristics. LWT - Food Science and Technology. 2016;**69**:175-184

[26] Yanık DK. Alternative to traditional olive pomace oil extraction systems: Microwave-assisted solvent extraction of oil from wet olive pomace. LWT - Food Science and Technology. 2017;**77**:45-51

[27] Kadi H, Moussaoui R, Djadoun S, et al. Microwave assisted extraction of olive oil pomace by acidic hexane. Iranian journal of chemistry and chemical engineering. 2016;**35**:73-79

[28] Malheiro R, Oliveira I, Vilas-Boas M, et al. Effect of microwave heating with different exposure times on physical and chemical parameters of olive oil. Food and Chemical Toxicology. 2009;**47**:92-97

[29] Leone A, Romaniello R, Tamborrino A, et al. Microwave and megasonics combined technology for a continuous olive oil process with enhanced extractability. Innovative Food Science and Emerging Technologies. 2017;**42**:56-63

[30] Leone A, Tamborrino A, Zagaria R, et al. Plant innovation in the olive

**18**

*Technological Innovation in the Olive Oil Production Chain*

Teknolojİler. Bornova, İzmir: Nobel

[8] Abenoza M, Benito M, Saldaña G, et al. Effects of pulsed electric field on yield extraction and quality of olive oil. Food and Bioprocess Technology.

[9] Puértolas E, Martínez de Marañón I. Olive oil pilot-production assisted by pulsed electric field: Impact on extraction yield, chemical parameters

[10] Clodoveo ML, Durante V, La Notte D. Working towards the development of innovative ultrasound equipment for the extraction of virgin olive oil. Ultrasonics Sonochemistry. 2013;**20**:1261-1270

[11] Aydar AY. Utilization of Response Surface Methodology in Optimization of Extraction of Plant Materials. United Kingdom: Intech Open; 2018. pp. 157-169

[12] Amirante R, Distaso E, Tamburrano P, et al. Acoustic cavitation by means ultrasounds in the extra virgin olive oil extraction process. Energy Procedia.

[13] Clodoveo ML. New advances in the development of innovative virgin olive oil extraction plants: Looking back to see the future. Food Research International. 2013;**54**:726-729

[14] Clodoveo ML, Hachicha Hbaieb R. Beyond the traditional virgin olive oil extraction systems: Searching innovative and sustainable plant engineering solutions. Food Research International. 2013;**54**:1926-1933

[15] Jiménez A, Beltrán G, Uceda M. High-power ultrasound in olive paste pretreatment. Effect on process yield and virgin olive oil characteristics. Ultrasonics

Sonochemistry. 2007;**14**:725-731

and sensory properties. Food Chemistry. 2015;**167**:497-502

yayıncılık; 2012

2013;**6**:1367-1373

2017;**126**:82-90

[1] Aydar AY, Bagdatlioglu N, Köseoglu O. Effect of ultrasound on olive oil extraction and optimization of ultrasound-assisted extraction of extra virgin olive oil by response surface methodology (RSM). Grasas y Aceites. 2017;**68**:1-11 [Epub ahead of print].

DOI: 10.3989/gya.1057162

efficiency-and-extra-virgin

DOI: 10.1159/000097916

Safety. 2014;**13**:135-154

[5] Clodoveo ML. An overview of emerging techniques in virgin olive oil extraction process: Strategies in the development of innovative plants. Journal of Agricultural Engineering. 2013;**44**:49-59 [Epub ahead of print].

DOI: 10.4081/jae.2013.s2.e60

Elsevier Inc.; 2014

[7] Baysal T, İçier F. Gıda Mühendİslİğİnde Isıl Olmayan

[6] Sun D-W. Emerging Technologies for Food Processing. 2nd ed. Dublin:

[3] Boskou D. Olive oil, Chemistry and Technology. Thessaloniki, Greece: AOCS; 2006. [Epub ahead of print].

[4] Clodoveo ML, Hbaieb RH, Kotti F, et al. Mechanical strategies to increase nutritional and sensory quality of virgin olive oil by modulating the endogenous enzyme activities. Comprehensive Reviews in Food Science and Food

[2] Veneziani G, Sordini B, Taticchi A, Esposto S, Selvaggini R, Urbani S, Di Maio I, Servili M. Improvement of Olive Oil Mechanical Extraction: New Technologies, Process Efficiency, and Extra Virgin Olive Oil Quality. Products from Olive Tree Dimitrios Boskou and Maria Lisa Clodoveo. IntechOpen. 2016. DOI: 10.5772/64796. Available from: https://www.intechopen.com/ books/products-from-olive-tree/ improvement-of-olive-oil-mechanicalextraction-new-technologies-process-

**References**

oil extraction process: A comparison of efficiency and energy consumption between microwave treatment and traditional malaxation of olive pastes. Journal of Food Engineering. 2015;**146**:44-52

[31] Clodoveo ML, Paduano A, Di Palmo T, et al. Engineering design and prototype development of a full scale ultrasound system for virgin olive oil by means of numerical and experimental analysis. Ultrasonics Sonochemistry. 2017;**37**:169-181

[32] Amirante R, Paduano A. Ultrasound in Olive Oil Extraction. United Kingdom: Intech Open; 2018. pp. 43-53

[33] Amirante R, Clodoveo ML. Developments in the design and construction of continuous full-scale ultrasonic devices for the EVOO industry. European Journal of Lipid Science and Technology. 2017;**119**:1-5

[34] Achat S, Tomao V, Madani K, et al. Direct enrichment of olive oil in oleuropein by ultrasound-assisted maceration at laboratory and pilot plant scale. Ultrasonics Sonochemistry. 2012;**19**:777-786

[35] Japón-Luján R, Janeiro P, De Castro MDL. Solid-liquid transfer of biophenols from olive leaves for the enrichment of edible oils by a dynamic ultrasound-assisted approach. Journal of Agricultural and Food Chemistry. 2008;**56**:7231-7235

[36] European Union Commission Regulation. (EEC) No 2568/91. Brussels: Official European Commission Journal; 1991

[37] Beltrán Ortega J, Martínez Gila DM, Aguilera Puerto D, et al. Novel technologies for monitoring the in-line quality of virgin olive oil during manufacturing and storage. Journal of the Science of Food and Agriculture. 2016;**96**:4644-4662

**21**

**Chapter 3**

**Abstract**

Does the Introduction of

Ultrasound in Extra-Virgin Olive

Oil Extraction Process Improve

the Income of the Olive Millers?

Simultaneous Increment of Yield

*Maria Lisa Clodoveo, Filomena Corbo and Riccardo Amirante*

Olive oil is an important product of the European agro-alimentary sector. The current olive oil extraction process can be further improved in order to overcome the weaknesses of the actual system in terms of non-continuity, reduction of oil in waste, sustainability, and improvement of quality both in the healthy and sensory perspective. Many innovative approaches have been developed to improve the olive oil extraction process. However, not all the proposed innovations have the opportunity to effectively reach a technological level of readiness close to "ready for the market." An innovator should simultaneously evaluate the aptitude of its invention to turn into a widely used commercial product both under the technological and the marketing perspectives. Under the technological point of view, an innovation should be effective, so, adequate to accomplish a purpose, and efficient, so, able to perform or functioning in the best possible manner with the least waste of time and effort. Under the marketing point of view, an innovation should be able to develop products that accurately and timely respond to customer needs, offering a valuable experience to the customer, exceeding his expectations. The innovative EVOO process based on ultrasound extraction has several advantages useful to improve olive miller income: higher yield extraction, higher polyphenols, and lower bitter

The First Technology for the

and Quality of the Product

and pungent taste than traditional EVOO samples.

technological level of readiness

**1. Introduction**

**Keywords:** olive oil, extraction process, innovative approaches, ultrasound,

basin; therefore it is usually considered as a traditional sector and not able to

Oliviculture is one of the most ancient economic activities of the Mediterranean

#### **Chapter 3**

*Technological Innovation in the Olive Oil Production Chain*

oil extraction process: A comparison of efficiency and energy consumption between microwave treatment and traditional malaxation of olive pastes. Journal of Food Engineering.

[31] Clodoveo ML, Paduano A, Di Palmo T, et al. Engineering design and prototype development of a full scale ultrasound system for virgin olive oil by means of numerical and experimental analysis. Ultrasonics Sonochemistry.

[32] Amirante R, Paduano A. Ultrasound in Olive Oil Extraction. United Kingdom:

Intech Open; 2018. pp. 43-53

[33] Amirante R, Clodoveo ML. Developments in the design and construction of continuous full-scale ultrasonic devices for the EVOO industry. European Journal of Lipid Science and Technology. 2017;**119**:1-5

[34] Achat S, Tomao V, Madani K, et al. Direct enrichment of olive oil in oleuropein by ultrasound-assisted maceration at laboratory and pilot plant scale. Ultrasonics Sonochemistry.

[35] Japón-Luján R, Janeiro P, De Castro MDL. Solid-liquid transfer of biophenols from olive leaves for the enrichment of edible oils by a dynamic ultrasound-assisted approach. Journal of Agricultural and Food Chemistry.

[36] European Union Commission Regulation. (EEC) No 2568/91. Brussels: Official European Commission Journal;

[37] Beltrán Ortega J, Martínez Gila DM, Aguilera Puerto D, et al. Novel technologies for monitoring the in-line quality of virgin olive oil during manufacturing and storage. Journal of the Science of Food and Agriculture.

2015;**146**:44-52

2017;**37**:169-181

2012;**19**:777-786

2008;**56**:7231-7235

2016;**96**:4644-4662

**20**

1991

Does the Introduction of Ultrasound in Extra-Virgin Olive Oil Extraction Process Improve the Income of the Olive Millers? The First Technology for the Simultaneous Increment of Yield and Quality of the Product

*Maria Lisa Clodoveo, Filomena Corbo and Riccardo Amirante*

#### **Abstract**

Olive oil is an important product of the European agro-alimentary sector. The current olive oil extraction process can be further improved in order to overcome the weaknesses of the actual system in terms of non-continuity, reduction of oil in waste, sustainability, and improvement of quality both in the healthy and sensory perspective. Many innovative approaches have been developed to improve the olive oil extraction process. However, not all the proposed innovations have the opportunity to effectively reach a technological level of readiness close to "ready for the market." An innovator should simultaneously evaluate the aptitude of its invention to turn into a widely used commercial product both under the technological and the marketing perspectives. Under the technological point of view, an innovation should be effective, so, adequate to accomplish a purpose, and efficient, so, able to perform or functioning in the best possible manner with the least waste of time and effort. Under the marketing point of view, an innovation should be able to develop products that accurately and timely respond to customer needs, offering a valuable experience to the customer, exceeding his expectations. The innovative EVOO process based on ultrasound extraction has several advantages useful to improve olive miller income: higher yield extraction, higher polyphenols, and lower bitter and pungent taste than traditional EVOO samples.

**Keywords:** olive oil, extraction process, innovative approaches, ultrasound, technological level of readiness

#### **1. Introduction**

Oliviculture is one of the most ancient economic activities of the Mediterranean basin; therefore it is usually considered as a traditional sector and not able to

positively enhance the economic and social development of European and North African countries where it is diffused.

Today, the olive miller has to directly face the market and all the multiple requirements of society. The growth of the olive miller company is linked to the development of its innovative capacity [1]. Understanding the factors that can determine the potential for innovation means understanding the main levers of intervention for the competitiveness and growth of an entrepreneurial activity [2] threatened by an evolving global context, which leads Italy in particular, among the European contest, to lose its positions of prestige always owned in the international context. In the last 20 years, we have therefore witnessed a "professional metamorphosis" of the role of the olive miller. In the last 20 years a metamorphosis occurred in the role of the olive miller inside his enterprise because the perspective with which the extraction process of extra-virgin olive oil can be considered, under a technological, chemical, biochemical, and sensorial point of view, has changed.

The term "extraction" in the olive oil sector is, in fact, a word to be considered obsolete in the light of the progress of knowledge developed over the last 20 years [3–9]. The word "extraction" is referred to any operation with which one "extracts" something within a specific technical process. Applied to the olive oil sector, the term "extraction" implies the following misunderstanding: the bottled virgin olive oil (product obtained exclusively with the use of mechanical systems), under the chemical and sensory point of view, is the same contained (as small lipid drops) within the elaioplasts (the subcellular organelles specialized in storing lipids inside the cells of the drupe).

This concept is wrong. In fact, during all the operations that start from the crushing, passing, across the malaxation, and the centrifugal separation of oil, a complex mass transfer occurs of those minor components (constitutive of the fruit, phenols, or of neo-formation, volatile compounds) from different tissues (epicarp, pulp, pit and seed) that compose the drupe to triglycerides organized in plastoglobules [8, 9]. Considering the occurrence of these phenomena, of a physical, chemical and biochemical nature, which make virgin olive oils different from the other lipidic plant matrices by composition and sensory and health properties, it is necessary to introduce a new term in the olive sector vocabulary that accurately reflects specificity and uniqueness of the complex transformation to which the process presides. Therefore, the verb "to extract" has to be replaced by the verb "to elaborate," already earlier adopted more than 10 years ago by Carlos Gómez Herrera of the Institute de la Grasa of Sevilla [10]. In fact, the verb "to elaborate" means "to develop a project through careful coordination and transformation of the basic elements to give them an arrangement and a complete form that responds to the desired purpose." In the olive oil world, the elaboration process of virgin olive oil has to allow to the olive miller the obtainment of the planned quantitative and qualitative results. This goal has to be planned at the moment of the raw material evaluation, or even before during the fruit development stage, at the moment in which the choice of the harvesting period occurs, nodal elements for the purposes of defining the characteristics of the product, and the interception of the preestablished market target [11, 12]. The word "extraction" relegates the oil miller of the past to the role of mute spectator who oversees a process whose outcomes are often unknown to him. He is a simple worker assigned to a manual labor only, who is not able to build solid strategy business based on segmentation, target, and product positioning; the verb "to elaborate" innovates the role and skills of the miller. He becomes the craftsman or the artisan, the one who exercises an art intended as an activity that requires a complex of technical knowledge at the service of a particular attitude [13].

**23**

advantage.

*Does the Introduction of Ultrasound in Extra-Virgin Olive Oil Extraction Process Improve…*

The modern miller masters the technology and the technological innovations. He is able to use the machines, regulating the macroscopic parameters of processing (specific energy, times, temperatures, atmosphere in contact with the product, and quantity of process water), with the aim to "modulate" the enzymatic activities that take place at the microscope level in the olive paste, consciously modifying the chemical, organoleptic, and health characteristics of the resulting virgin oil [9]. The word "modular" is a term borrowed from the world of music that refers to the ability to vary a sound or a tone, to achieve a harmonious effect. It is an indispensable term to describe the activity of the miller that, in a very short period of time, must make a series of decisive choices to obtain an extra-virgin olive oil, with a pleasant overall sensation, due to the perception of its components, phenolics and volatiles, which act as olfactory-gustatory, tactile, and kinesthetic stimuli balance

However, the relationship of the olive oil sector with technological innovation is controversial. The olive and olive oil sector can be considered a technologically conservative productive system, that is, with a limited introduction of innovations compared to other sectors of agro-food [14]. This approach is apparently consistent with the behavior of the typical consumer. Consumers are linked to a model of consumption of extra-virgin olive oil based on habit and bound to a taste that has consolidated over time. People are reluctant to change, despite the pressure of a communication and training activities aimed to increase in the culture of olive oil for the improvement of the competitiveness of high-quality

On the contrary, the global agri-food system seems to be constantly encouraged to develop innovations in products, processes, or services able to face an increasingly pressing demand for healthy, quality food, able to satisfy, at the same time, healthy and hedonistic needs, with certain origin, and that they can offer a strong experiential dimension. In the agri-food sector, therefore, the tendency of the market is the creation of a growing demand for an increasingly differentiated and

Technological innovation, and the product segmentation that derives from it, is the only path that can be followed by the olive oil sector, which must increase competitiveness. The exploitation of technological innovations is the only useful tool to increase production efficiency, product quality, process sustainability, and

**2. The first technology for the simultaneous increment of yield and** 

Public and private research bodies are constantly working on innovative approaches to develop new products, processes or organizational models in the olive oil sector. However, the conversion of these research results to industrial innovations considerably more complex than generally believed. In practice, not all inventions, that is, new solutions developed in laboratories in response to a technical problem, can be transformed into innovations, then into new products or processes suitable for commercial exploitation for a competitive supply chain

In the olive oil sector, the levers that guide research and development of innovations are constituted by the need to favor, during the extraction process, the separation of the highest quantity of oil, and of the best quality, modulating appropriately the complex series of physical transformations, chemical-physical, chemical, and biochemical within the olive paste. The increase in yield and product quality is an

segmented product, in countercurrent with the world of olive oil.

ultimately the profitability of the sector.

**quality of the extra-virgin olive oil**

*DOI: http://dx.doi.org/10.5772/intechopen.81666*

between them.

products [15, 16].

*Does the Introduction of Ultrasound in Extra-Virgin Olive Oil Extraction Process Improve… DOI: http://dx.doi.org/10.5772/intechopen.81666*

The modern miller masters the technology and the technological innovations. He is able to use the machines, regulating the macroscopic parameters of processing (specific energy, times, temperatures, atmosphere in contact with the product, and quantity of process water), with the aim to "modulate" the enzymatic activities that take place at the microscope level in the olive paste, consciously modifying the chemical, organoleptic, and health characteristics of the resulting virgin oil [9]. The word "modular" is a term borrowed from the world of music that refers to the ability to vary a sound or a tone, to achieve a harmonious effect. It is an indispensable term to describe the activity of the miller that, in a very short period of time, must make a series of decisive choices to obtain an extra-virgin olive oil, with a pleasant overall sensation, due to the perception of its components, phenolics and volatiles, which act as olfactory-gustatory, tactile, and kinesthetic stimuli balance between them.

However, the relationship of the olive oil sector with technological innovation is controversial. The olive and olive oil sector can be considered a technologically conservative productive system, that is, with a limited introduction of innovations compared to other sectors of agro-food [14]. This approach is apparently consistent with the behavior of the typical consumer. Consumers are linked to a model of consumption of extra-virgin olive oil based on habit and bound to a taste that has consolidated over time. People are reluctant to change, despite the pressure of a communication and training activities aimed to increase in the culture of olive oil for the improvement of the competitiveness of high-quality products [15, 16].

On the contrary, the global agri-food system seems to be constantly encouraged to develop innovations in products, processes, or services able to face an increasingly pressing demand for healthy, quality food, able to satisfy, at the same time, healthy and hedonistic needs, with certain origin, and that they can offer a strong experiential dimension. In the agri-food sector, therefore, the tendency of the market is the creation of a growing demand for an increasingly differentiated and segmented product, in countercurrent with the world of olive oil.

Technological innovation, and the product segmentation that derives from it, is the only path that can be followed by the olive oil sector, which must increase competitiveness. The exploitation of technological innovations is the only useful tool to increase production efficiency, product quality, process sustainability, and ultimately the profitability of the sector.

#### **2. The first technology for the simultaneous increment of yield and quality of the extra-virgin olive oil**

Public and private research bodies are constantly working on innovative approaches to develop new products, processes or organizational models in the olive oil sector. However, the conversion of these research results to industrial innovations considerably more complex than generally believed. In practice, not all inventions, that is, new solutions developed in laboratories in response to a technical problem, can be transformed into innovations, then into new products or processes suitable for commercial exploitation for a competitive supply chain advantage.

In the olive oil sector, the levers that guide research and development of innovations are constituted by the need to favor, during the extraction process, the separation of the highest quantity of oil, and of the best quality, modulating appropriately the complex series of physical transformations, chemical-physical, chemical, and biochemical within the olive paste. The increase in yield and product quality is an

*Technological Innovation in the Olive Oil Production Chain*

African countries where it is diffused.

view, has changed.

the drupe).

positively enhance the economic and social development of European and North

Today, the olive miller has to directly face the market and all the multiple requirements of society. The growth of the olive miller company is linked to the development of its innovative capacity [1]. Understanding the factors that can determine the potential for innovation means understanding the main levers of intervention for the competitiveness and growth of an entrepreneurial activity [2] threatened by an evolving global context, which leads Italy in particular, among the European contest, to lose its positions of prestige always owned in the international context. In the last 20 years, we have therefore witnessed a "professional metamorphosis" of the role of the olive miller. In the last 20 years a metamorphosis occurred in the role of the olive miller inside his enterprise because the perspective with which the extraction process of extra-virgin olive oil can be considered, under a technological, chemical, biochemical, and sensorial point of

The term "extraction" in the olive oil sector is, in fact, a word to be considered obsolete in the light of the progress of knowledge developed over the last 20 years [3–9]. The word "extraction" is referred to any operation with which one "extracts" something within a specific technical process. Applied to the olive oil sector, the term "extraction" implies the following misunderstanding: the bottled virgin olive oil (product obtained exclusively with the use of mechanical systems), under the chemical and sensory point of view, is the same contained (as small lipid drops) within the elaioplasts (the subcellular organelles specialized in storing lipids inside the cells of

This concept is wrong. In fact, during all the operations that start from the crushing, passing, across the malaxation, and the centrifugal separation of oil, a complex mass transfer occurs of those minor components (constitutive of the fruit, phenols, or of neo-formation, volatile compounds) from different tissues (epicarp, pulp, pit and seed) that compose the drupe to triglycerides organized in plastoglobules [8, 9]. Considering the occurrence of these phenomena, of a physical, chemical and biochemical nature, which make virgin olive oils different from the other lipidic plant matrices by composition and sensory and health properties, it is necessary to introduce a new term in the olive sector vocabulary that accurately reflects specificity and uniqueness of the complex transformation to which the process presides. Therefore, the verb "to extract" has to be replaced by the verb "to elaborate," already earlier adopted more than 10 years ago by Carlos Gómez Herrera of the Institute de la Grasa of Sevilla [10]. In fact, the verb "to elaborate" means "to develop a project through careful coordination and transformation of the basic elements to give them an arrangement and a complete form that responds to the desired purpose." In the olive oil world, the elaboration process of virgin olive oil has to allow to the olive miller the obtainment of the planned quantitative and qualitative results. This goal has to be planned at the moment of the raw material evaluation, or even before during the fruit development stage, at the moment in which the choice of the harvesting period occurs, nodal elements for the purposes of defining the characteristics of the product, and the interception of the preestablished market target [11, 12]. The word "extraction" relegates the oil miller of the past to the role of mute spectator who oversees a process whose outcomes are often unknown to him. He is a simple worker assigned to a manual labor only, who is not able to build solid strategy business based on segmentation, target, and product positioning; the verb "to elaborate" innovates the role and skills of the miller. He becomes the craftsman or the artisan, the one who exercises an art intended as an activity that requires a complex of technical knowledge at the service of a

**22**

particular attitude [13].

antithetical objective, which cannot be achieved simultaneously with the currently widespread technologies but which must be pursued to guarantee fair profitability for the operators of the sector.

Innovations can be distinguished by the degree of novelty with respect to existing technology, organization, and demand, in two different types: incremental innovations and radical innovations. Incremental innovations involve the improvement of a process, of a product or service with respect to a specific existing model or process. Radical innovations represent a break with existing products or processes. From these innovations, in some cases, new industries or market segments can arise. Incremental innovations are very numerous, while radical ones are rarer.

Considering the machinery for the oil sector, the last radical innovation is represented by the introduction of centrifugal separation of oils and the transformation of the obsolete pressure extraction system, characterized by low working capacity, high labor demand, and poor hygienic standards, in the modern "continuous" system, highly effective and efficient. This innovation dates back to the 1970s. It involved the need to combine the decanter, the centrifuge with horizontal axis that continuously separates the oil from the olive paste, with the malaxers. The malaxer is a machine that operates in batch and that is necessary to favor, thanks to the heat exchange and agitation, the coalescence of minute droplets of oil into larger diameter drops, able to be separated in a centrifugal field and to guarantee satisfactory yields [8, 9].

Most of the incremental innovations developed in the last 30 years have had the purpose to improve the performance of the malaxers. The aim of these innovation was optimizing the machine geometry and the heat exchange (also by means the introduction of heat exchangers), improving the ratio between volumes of olive paste and exchange surface, to reduce treatment times and the number of malaxers necessary to guarantee continuity to the process. Observing the principles on which the incremental innovations were based, it is possible to state that the levers experimented to design new machines, able to improve the extraction yields and reduce the residual fat present in the by-products, are, on the physical point of view, the same principles on which traditionally the olive oil technology has always been based: heating and stirring to reduce the viscosity of the olive paste. We can consider, with good margins of certainty, that every technological effort based on the optimization of these three factors has reached the apex of applicability and that the machines currently on the market are the best performing. The perspectives for improvement are technically feasible if we persevere with the already consolidated approaches.

Looking at the characteristics of the oil by-products, it is clear that there is still room to increase the efficacy and efficiency of the machines destined for olive oil extraction. And here it is perhaps the case to dwell on the terms "effectiveness" and "efficiency," often used indistinctly as synonyms but which actually reflect two distinct concepts. Effectiveness, in fact, indicates the ability to achieve the set objective, while efficiency evaluates the ability to do so using the minimum necessary resources. In the case of olive plant engineering, we can say that a technology is effective if it is able to increase yields and antioxidant content by reducing the losses in by-products and is effective if it achieves these goals in a sustainable manner, reducing energy costs for the benefit of business economies and the impact on the environment.

Effectiveness and efficiency can be achievable goals also thanks to the use of emerging technologies [17–19]. Emerging technologies are technologies available at the experimental level, which have already shown advantages in other fields of application and whose developments are now considered extremely promising in the coming decades. In the case of the extraction of extra-virgin olive oil, emerging technologies must ensure the simultaneous achievement of two different effects: a

**25**

**Figure 1.**

*Ultrasonics AG.*

*Does the Introduction of Ultrasound in Extra-Virgin Olive Oil Extraction Process Improve…*

oil sector in the near future, there are microwaves and ultrasounds [20–25].

mechanical and a thermal effect. The mechanical effect comprises the breakage of the cells passed intact to the crusher and the release of further oil and minor compounds. The mild thermal effect is useful to accelerate, by means of the hydrophobic effect, the coalescence of minute lipid droplets. Among the emerging technologies that are spreading in the food industry, candidates to become real-scale plants in the

Microwaves are electromagnetic radiations with frequencies between 300 MHz and 300 GHz [21]. They determine powerful and macroscopic thermal effects in the matrix due to the effect that the electromagnetic radiation exerts on the polar molecules, such as water. The polar molecules rotate with high frequency to align their dipole to the electromagnetic field, generating frictions with the adjacent molecules that induce a rapid and inhomogeneous heating. Because of thermal spots, areas where there is concentration, due to the inhomogeneity of the radiation and a high thermal increase, the dilatation of the aqueous phase of the cytoplasm induces a

Ultrasounds are sound waves with frequencies from 20 kHz to some GHz, higher than the audible limit of the human ear. At low frequencies, between 20 and 40 kHz, they determine an evident mechanical effect, due to the phenomenon of cavitation, which contributes significantly to the breakage of the intact past cells to the crusher, freeing the lipid content (**Figure 1**); the thermal effect is mild and

Tests aimed at measuring the ability of the two technologies to be transferred in the design of real-scale plants and implemented in modern full-scale mills have been realized, and the performances in terms of effectiveness and efficiency have been

*Cavitation breaks the intact past cells to the crusher freeing the lipid content. Picture by courtesy of Weber* 

*DOI: http://dx.doi.org/10.5772/intechopen.81666*

mild mechanical action of breaking of the cell walls.

negligible [20].

measured.

*Does the Introduction of Ultrasound in Extra-Virgin Olive Oil Extraction Process Improve… DOI: http://dx.doi.org/10.5772/intechopen.81666*

mechanical and a thermal effect. The mechanical effect comprises the breakage of the cells passed intact to the crusher and the release of further oil and minor compounds. The mild thermal effect is useful to accelerate, by means of the hydrophobic effect, the coalescence of minute lipid droplets. Among the emerging technologies that are spreading in the food industry, candidates to become real-scale plants in the oil sector in the near future, there are microwaves and ultrasounds [20–25].

Microwaves are electromagnetic radiations with frequencies between 300 MHz and 300 GHz [21]. They determine powerful and macroscopic thermal effects in the matrix due to the effect that the electromagnetic radiation exerts on the polar molecules, such as water. The polar molecules rotate with high frequency to align their dipole to the electromagnetic field, generating frictions with the adjacent molecules that induce a rapid and inhomogeneous heating. Because of thermal spots, areas where there is concentration, due to the inhomogeneity of the radiation and a high thermal increase, the dilatation of the aqueous phase of the cytoplasm induces a mild mechanical action of breaking of the cell walls.

Ultrasounds are sound waves with frequencies from 20 kHz to some GHz, higher than the audible limit of the human ear. At low frequencies, between 20 and 40 kHz, they determine an evident mechanical effect, due to the phenomenon of cavitation, which contributes significantly to the breakage of the intact past cells to the crusher, freeing the lipid content (**Figure 1**); the thermal effect is mild and negligible [20].

Tests aimed at measuring the ability of the two technologies to be transferred in the design of real-scale plants and implemented in modern full-scale mills have been realized, and the performances in terms of effectiveness and efficiency have been measured.

#### **Figure 1.** *Cavitation breaks the intact past cells to the crusher freeing the lipid content. Picture by courtesy of Weber Ultrasonics AG.*

*Technological Innovation in the Olive Oil Production Chain*

for the operators of the sector.

are rarer.

yields [8, 9].

antithetical objective, which cannot be achieved simultaneously with the currently widespread technologies but which must be pursued to guarantee fair profitability

Innovations can be distinguished by the degree of novelty with respect to existing technology, organization, and demand, in two different types: incremental innovations and radical innovations. Incremental innovations involve the improvement of a process, of a product or service with respect to a specific existing model or process. Radical innovations represent a break with existing products or processes. From these innovations, in some cases, new industries or market segments can arise. Incremental innovations are very numerous, while radical ones

Considering the machinery for the oil sector, the last radical innovation is represented by the introduction of centrifugal separation of oils and the transformation of the obsolete pressure extraction system, characterized by low working capacity, high labor demand, and poor hygienic standards, in the modern "continuous" system, highly effective and efficient. This innovation dates back to the 1970s. It involved the need to combine the decanter, the centrifuge with horizontal axis that continuously separates the oil from the olive paste, with the malaxers. The malaxer is a machine that operates in batch and that is necessary to favor, thanks to the heat exchange and agitation, the coalescence of minute droplets of oil into larger diameter drops, able to be separated in a centrifugal field and to guarantee satisfactory

Most of the incremental innovations developed in the last 30 years have had the purpose to improve the performance of the malaxers. The aim of these innovation was optimizing the machine geometry and the heat exchange (also by means the introduction of heat exchangers), improving the ratio between volumes of olive paste and exchange surface, to reduce treatment times and the number of malaxers necessary to guarantee continuity to the process. Observing the principles on which the incremental innovations were based, it is possible to state that the levers experimented to design new machines, able to improve the extraction yields and reduce the residual fat present in the by-products, are, on the physical point of view, the same principles on which traditionally the olive oil technology has always been based: heating and stirring to reduce the viscosity of the olive paste. We can consider, with good margins of certainty, that every technological effort based on the optimization of these three factors has reached the apex of applicability and that the machines currently on the market are the best performing. The perspectives for improvement are technically feasible if we persevere with the already consolidated approaches. Looking at the characteristics of the oil by-products, it is clear that there is still room to increase the efficacy and efficiency of the machines destined for olive oil extraction. And here it is perhaps the case to dwell on the terms "effectiveness" and "efficiency," often used indistinctly as synonyms but which actually reflect two distinct concepts. Effectiveness, in fact, indicates the ability to achieve the set objective, while efficiency evaluates the ability to do so using the minimum necessary resources. In the case of olive plant engineering, we can say that a technology is effective if it is able to increase yields and antioxidant content by reducing the losses in by-products and is effective if it achieves these goals in a sustainable manner, reducing energy costs for the benefit of business economies and the impact on the environment. Effectiveness and efficiency can be achievable goals also thanks to the use of emerging technologies [17–19]. Emerging technologies are technologies available at the experimental level, which have already shown advantages in other fields of application and whose developments are now considered extremely promising in the coming decades. In the case of the extraction of extra-virgin olive oil, emerging technologies must ensure the simultaneous achievement of two different effects: a

**24**

From the point of view of effectiveness, and therefore of the capacity to increase extraction yields, the theoretical premises based on the intrinsic characteristics of the two technologies have been confirmed by the experimental evidence. In relation to the heating times, the microwaves showed the ability to significantly reduce the duration of the malaxation with the same extraction yields. On the contrary, the mechanical action of the ultrasounds, clearly superior to the mechanical action of the microwaves, combined a noticeable increase in extraction yields with a time reduction.

Two technologies compared with two antithetical effects. What strategies can be applied to design the plant that will most likely contribute to the improvement of the process?

Alongside the efficacy observations summarized in terms of contraction of the malaxation times (one-tenth for the microwaves and one third for the ultrasounds), the considerations in terms of efficiency were decisive. The tests carried out in order to measure the efficiency of the processes have revealed how the microwaves represent a technology, at present, extremely energizing and not compatible with the more recent guidelines of the industry 4.0, which privilege processes able to preserve the natural resources.

Experimental evidence has led to the exclusion of the industrial scale-up of microwave technology: the only advantage constituted by the significant contraction of processing times did not match the desired increase in yields [21]; the lack of energy efficiency, moreover, represented a threat of increasing production costs incompatible with the production context that offers limited margins of profit.

Promising, on the contrary, was the premise for the implementation of ultrasound technology linked to the positive increase in yield, the mild thermal effect, and the high energy efficiency: three evidences that opened the prospect of achieving the goal of increasing yields and the concentration of minor compounds, reducing production costs, and improving company profit margins [20, 23–25].

How is it possible to pass from the batch laboratory device, which is able to treat limited quantities of olive paste (about 3 kg) to plants that operate continuously, working tens of quintals of olives?

It is here that it becomes fundamental to combine the multidisciplinary skills of the research groups. From the collaboration between knowledge areas, food technologies, food chemistry, and mechanical engineering, a design strategy has been realized. The starting point was the definition of the ideal geometry and then on the energy calculations necessary to create a plant able to guarantee the conversion of the conditions tested in batch (lab-scale) in an ultrasonic treatment administered continuously (full-scale).

In terms of geometry, the construction of an ultrasonic system must start from the characteristics of the transducers present on the market and from the flexibility that these can offer during the design phase, also with a look at the possibility of realizing plant solutions suited to the different working capacities of the oil mills. The most commonly used transducers are the so-called probe transducers. The first prototypes made have favored this model because it integrates well with the triple tube heat exchangers already widespread on the market. This combination was chosen to maximize the effects of ultrasound, which are emphasized by the simultaneous heating of the oil paste, which, by reducing the viscosity of the fluid, promotes the propagation of the wave in the medium**.** Fluid dynamic simulation tests, carried out simultaneously with the experimental tests, have however highlighted some limitations of this geometry, proving how long, tortuous, and costly is the path necessary to develop an innovation.

So the next step was the design and build of an ultrasound system based on the use of plate transducers. An octagonal section system has been created that combines ultrasonic treatment with heat exchange (**Figure 2**). It allows a thermal

**27**

**Figure 2.**

*the right).*

*Does the Introduction of Ultrasound in Extra-Virgin Olive Oil Extraction Process Improve…*

conditioning of the olive paste aimed at both heating and cooling, depending on the environmental and territorial context in which the technology is implemented. The sizing, based on the calculation of the specific energy to be administered, has shown that the amount of energy necessary to maximize the advantages obtainable from the use of ultrasound, for frequencies between 20 and 40 kHz, is equal to about 18,000 J/kg. 18,000 J/kg is a number that can mean nothing if not compared to other process operations [25]. In order to make clear the meaning of ultrasonic treatment, it is sufficient to think that the specific energy transferred from a

The ultrasonic treatment, in this perspective, can be considered a sort of finishing of the crushing step. The ultrasonic treatment of the olive paste is fully classified as a mild technology. It is a delicate technology that allows to combine, for the first time in the history of the development of oil mills, the increase in yield (more than 1 kg of oil per 100 kg of olives) with the increase of the content in polyphenolic substances, minimizing the thermal and oxidative damage, demonstrated by the chemical analyzes aimed at the product classification and by the

The use of ultrasound in the oil sector is part of key enabling technology, as it represents a technological solution capable of revitalizing the production system, and meets the social challenges related to food safety, sustainable agriculture, and bio-economy as it represents an efficient production system that can accelerate the

Ultrasounds also concretely open the way to a production model that, consistent with the principles of circular economy, leads the mills to exploit the potential to

*The inner part of the sono-heat-exchanger (on the left). The external structure of the sono-heat-exchanger (on* 

*DOI: http://dx.doi.org/10.5772/intechopen.81666*

panel test.

mechanical crusher is approximately 30,000–36,000 J/kg.

conversion of companies toward sustainability.

#### *Does the Introduction of Ultrasound in Extra-Virgin Olive Oil Extraction Process Improve… DOI: http://dx.doi.org/10.5772/intechopen.81666*

conditioning of the olive paste aimed at both heating and cooling, depending on the environmental and territorial context in which the technology is implemented. The sizing, based on the calculation of the specific energy to be administered, has shown that the amount of energy necessary to maximize the advantages obtainable from the use of ultrasound, for frequencies between 20 and 40 kHz, is equal to about 18,000 J/kg. 18,000 J/kg is a number that can mean nothing if not compared to other process operations [25]. In order to make clear the meaning of ultrasonic treatment, it is sufficient to think that the specific energy transferred from a mechanical crusher is approximately 30,000–36,000 J/kg.

The ultrasonic treatment, in this perspective, can be considered a sort of finishing of the crushing step. The ultrasonic treatment of the olive paste is fully classified as a mild technology. It is a delicate technology that allows to combine, for the first time in the history of the development of oil mills, the increase in yield (more than 1 kg of oil per 100 kg of olives) with the increase of the content in polyphenolic substances, minimizing the thermal and oxidative damage, demonstrated by the chemical analyzes aimed at the product classification and by the panel test.

The use of ultrasound in the oil sector is part of key enabling technology, as it represents a technological solution capable of revitalizing the production system, and meets the social challenges related to food safety, sustainable agriculture, and bio-economy as it represents an efficient production system that can accelerate the conversion of companies toward sustainability.

Ultrasounds also concretely open the way to a production model that, consistent with the principles of circular economy, leads the mills to exploit the potential to

#### **Figure 2.**

*The inner part of the sono-heat-exchanger (on the left). The external structure of the sono-heat-exchanger (on the right).*

*Technological Innovation in the Olive Oil Production Chain*

the process?

preserve the natural resources.

working tens of quintals of olives?

the path necessary to develop an innovation.

continuously (full-scale).

From the point of view of effectiveness, and therefore of the capacity to increase extraction yields, the theoretical premises based on the intrinsic characteristics of the two technologies have been confirmed by the experimental evidence. In relation to the heating times, the microwaves showed the ability to significantly reduce the duration of the malaxation with the same extraction yields. On the contrary, the mechanical action of the ultrasounds, clearly superior to the mechanical action of the microwaves,

Two technologies compared with two antithetical effects. What strategies can be applied to design the plant that will most likely contribute to the improvement of

Alongside the efficacy observations summarized in terms of contraction of the malaxation times (one-tenth for the microwaves and one third for the ultrasounds), the considerations in terms of efficiency were decisive. The tests carried out in order to measure the efficiency of the processes have revealed how the microwaves represent a technology, at present, extremely energizing and not compatible with the more recent guidelines of the industry 4.0, which privilege processes able to

Experimental evidence has led to the exclusion of the industrial scale-up of microwave technology: the only advantage constituted by the significant contraction of processing times did not match the desired increase in yields [21]; the lack of energy efficiency, moreover, represented a threat of increasing production costs incompatible with the production context that offers limited margins of profit. Promising, on the contrary, was the premise for the implementation of ultrasound technology linked to the positive increase in yield, the mild thermal effect, and the high energy efficiency: three evidences that opened the prospect of achieving the goal of increasing yields and the concentration of minor compounds, reduc-

ing production costs, and improving company profit margins [20, 23–25].

How is it possible to pass from the batch laboratory device, which is able to treat limited quantities of olive paste (about 3 kg) to plants that operate continuously,

It is here that it becomes fundamental to combine the multidisciplinary skills of the research groups. From the collaboration between knowledge areas, food technologies, food chemistry, and mechanical engineering, a design strategy has been realized. The starting point was the definition of the ideal geometry and then on the energy calculations necessary to create a plant able to guarantee the conversion of the conditions tested in batch (lab-scale) in an ultrasonic treatment administered

In terms of geometry, the construction of an ultrasonic system must start from the characteristics of the transducers present on the market and from the flexibility that these can offer during the design phase, also with a look at the possibility of realizing plant solutions suited to the different working capacities of the oil mills. The most commonly used transducers are the so-called probe transducers. The first prototypes made have favored this model because it integrates well with the triple tube heat exchangers already widespread on the market. This combination was chosen to maximize the effects of ultrasound, which are emphasized by the simultaneous heating of the oil paste, which, by reducing the viscosity of the fluid, promotes the propagation of the wave in the medium**.** Fluid dynamic simulation tests, carried out simultaneously with the experimental tests, have however highlighted some limitations of this geometry, proving how long, tortuous, and costly is

So the next step was the design and build of an ultrasound system based on the use of plate transducers. An octagonal section system has been created that combines ultrasonic treatment with heat exchange (**Figure 2**). It allows a thermal

combined a noticeable increase in extraction yields with a time reduction.

**26**

profitably integrate the use of differentiated pressing within the processing line. The use of the pitting machine, which is not widespread today due to the known yield losses, can be stimulated by the use of ultrasounds which have a positive effect on the extractability of the oil. The elimination of the core before the product enters the processing line has the advantage of increasing the working capacity of the plants and improving energy efficiency and offers the possibility of allocating the de-stoned pomace to more profitable purposes.

The implementation of ultrasound in the olive oil extraction process is characterized by a high level of technological maturity (TRL, technology readiness levels) of 8, which corresponds to the development of the system and its validation on a real scale.

#### **3. The introduction of ultrasound in extra-virgin olive oil extraction process can improve the income of the olive millers**

**Table 1** shows the economic comparison between the traditional system and the innovative system with ultrasounds. The simulation is done on a crusher with a working capacity of 1500 kg/h that works 10 h a day for 80 days, about 3 months.

Assuming an average price of olives equal to €90 per quintal, and the selling price of oil equal to €7, without including in the comparison the premium price of oil extracted by ultrasound due to the increase in polyphenols and the highest health value, an increase in incomings of 116,700 euros is achieved. The return on investment can be quantified in just 2 years.


#### **Table 1.**

*Simulation of economic budget comparison between the traditional system and the innovative system equipped with ultrasounds during a single harvesting season.*

**29**

*Does the Introduction of Ultrasound in Extra-Virgin Olive Oil Extraction Process Improve…*

The introduction of ultrasound in extra-virgin olive oil extraction is the first technology for the simultaneous increment of yield and quality of the product. The innovative EVOO process based on ultrasound extraction has several advantages useful to improve olive miller income: higher yield extraction, higher polyphenols,

This work has been supported by the AGER 2 Project, Grant No. 2016-0174, COMPETITIVE - Claims of Olive oil to iMProvE The market ValuE of the product. Ager is a project that creates a network of banking origin Foundations to support and to promote innovative research projects in the agri-food sector (Fondazione Cariplo, Fondazione Cassa di Risparmio di Bologna, Fondazione Cassa di Risparmio di Cuneo, Ente Cassa di Risparmio di Firenze, Fondazione Cassa di Risparmio di Ferrara, Fondazione Cassa di Risparmio Modena, Fondazione Cassa di Risparmio di Padova e Rovigo, Fondazione Cassa di Risparmio di Parma, Fondazione Cassa di Risparmio di Teramo, Fondazione Cassa di Risparmio di Trento e Rovereto, Fondazione Cassa di Risparmio di Udine e Pordenone, Fondazione di Venezia, Fondazione Cassa di Risparmio di Vercelli, Fondazione Cassa di Risparmio di Bolzano, Fondazione Cassa di Risparmio di Modena, Fondazione di Sardegna,

The author(s) declare(s) that there is no conflict of interest regarding the

and lower bitter and pungent taste than traditional EVOO samples.

*DOI: http://dx.doi.org/10.5772/intechopen.81666*

Fondazione Cassa di Risparmio CON IL SUD).

**4. Conclusion**

**Acknowledgements**

**Conflict of interest**

publication of this article.

*Does the Introduction of Ultrasound in Extra-Virgin Olive Oil Extraction Process Improve… DOI: http://dx.doi.org/10.5772/intechopen.81666*

#### **4. Conclusion**

*Technological Innovation in the Olive Oil Production Chain*

de-stoned pomace to more profitable purposes.

investment can be quantified in just 2 years.

scale.

3 months.

profitably integrate the use of differentiated pressing within the processing line. The use of the pitting machine, which is not widespread today due to the known yield losses, can be stimulated by the use of ultrasounds which have a positive effect on the extractability of the oil. The elimination of the core before the product enters the processing line has the advantage of increasing the working capacity of the plants and improving energy efficiency and offers the possibility of allocating the

The implementation of ultrasound in the olive oil extraction process is characterized by a high level of technological maturity (TRL, technology readiness levels) of 8, which corresponds to the development of the system and its validation on a real

**3. The introduction of ultrasound in extra-virgin olive oil extraction** 

**Table 1** shows the economic comparison between the traditional system and the innovative system with ultrasounds. The simulation is done on a crusher with a working capacity of 1500 kg/h that works 10 h a day for 80 days, about

Assuming an average price of olives equal to €90 per quintal, and the selling price of oil equal to €7, without including in the comparison the premium price of oil extracted by ultrasound due to the increase in polyphenols and the highest health value, an increase in incomings of 116,700 euros is achieved. The return on

*Simulation of economic budget comparison between the traditional system and the innovative system equipped* 

**process can improve the income of the olive millers**

**28**

**Table 1.**

*with ultrasounds during a single harvesting season.*

The introduction of ultrasound in extra-virgin olive oil extraction is the first technology for the simultaneous increment of yield and quality of the product. The innovative EVOO process based on ultrasound extraction has several advantages useful to improve olive miller income: higher yield extraction, higher polyphenols, and lower bitter and pungent taste than traditional EVOO samples.

#### **Acknowledgements**

This work has been supported by the AGER 2 Project, Grant No. 2016-0174, COMPETITIVE - Claims of Olive oil to iMProvE The market ValuE of the product. Ager is a project that creates a network of banking origin Foundations to support and to promote innovative research projects in the agri-food sector (Fondazione Cariplo, Fondazione Cassa di Risparmio di Bologna, Fondazione Cassa di Risparmio di Cuneo, Ente Cassa di Risparmio di Firenze, Fondazione Cassa di Risparmio di Ferrara, Fondazione Cassa di Risparmio Modena, Fondazione Cassa di Risparmio di Padova e Rovigo, Fondazione Cassa di Risparmio di Parma, Fondazione Cassa di Risparmio di Teramo, Fondazione Cassa di Risparmio di Trento e Rovereto, Fondazione Cassa di Risparmio di Udine e Pordenone, Fondazione di Venezia, Fondazione Cassa di Risparmio di Vercelli, Fondazione Cassa di Risparmio di Bolzano, Fondazione Cassa di Risparmio di Modena, Fondazione di Sardegna, Fondazione Cassa di Risparmio CON IL SUD).

#### **Conflict of interest**

The author(s) declare(s) that there is no conflict of interest regarding the publication of this article.

*Technological Innovation in the Olive Oil Production Chain*

#### **Author details**

Maria Lisa Clodoveo1 \*, Filomena Corbo2 and Riccardo Amirante3

1 Interdisciplinary Department of Medicine, University of Bari, Bari, Italy

2 Department of Pharmacy-Pharmaceutical Science, University of Bari, Bari, Italy

3 Department of Mechanics, Mathematics and Management, Polytechnic University of Bari, Bari, Italy

\*Address all correspondence to: marialisa.clodoveo@uniba.it

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**31**

*Does the Introduction of Ultrasound in Extra-Virgin Olive Oil Extraction Process Improve…*

[8] Clodoveo ML. Malaxation: Influence

[9] Clodoveo ML, Hbaieb RH, Kotti F, Mugnozza GS, Gargouri M. Mechanical strategies to increase nutritional and sensory quality of virgin olive oil by modulating the endogenous enzyme activities. Comprehensive Reviews in Food Science and Food Safety.

[10] Gómez Herrera C. Matter transfer during virgin olive oil elaboration. Grasas y Aceites. 2007;**58**(2):

[11] Clodoveo ML, Dipalmo T, Crupi P, Durante V, Pesce V, Maiellaro I, et al. Comparison between different flavored

[12] De Luca M, Restuccia D, Clodoveo ML, Puoci F, Ragno G. Chemometric analysis for discrimination of extra virgin olive oils from whole and stoned olive pastes. Food Chemistry.

[13] Clodoveo ML, Dipalmo T, Schiano C, La Notte D, Pati S. What's now, what's new and what's next in virgin olive oil elaboration systems? A perspective on current knowledge and future trends. Journal of Agricultural Engineering.

[14] Clodoveo ML, Camposeo S, De Gennaro B, Pascuzzi S, Roselli L. In the ancient world, virgin olive oil was called "liquid gold" by Homer and "the great healer" by Hippocrates. Why has this mythic image been forgotten? Food Research International.

olive oil production techniques: Healthy value and process efficiency. Plant Foods for Human Nutrition.

on virgin olive oil quality. Past, present and future—An overview. Trends in Food Science & Technology.

2012;**25**(1):13-23

2014;**13**(2):135-154

2016;**71**(1):81-87

2016;**202**:432-437

2014;**45**(2):49-59

2014;**62**:1062-1068

194-205

*DOI: http://dx.doi.org/10.5772/intechopen.81666*

[1] Amirante R, Clodoveo ML, Distaso E, Ruggiero F, Tamburrano P. A trigeneration plant fuelled with olive tree pruning residues in Apulia: An energetic and economic analysis. Renewable

[2] Restuccia D, Clodoveo ML, Corbo F, Loizzo MR. De-stoning technology for improving olive oil nutritional and sensory features: The right idea at the wrong time. Food Research International. 2018;**106**:636-646

[3] Amirante P, Clodoveo ML, Dugo G, Leone A, Tamborrino A. Advance technology in virgin olive oil production from traditional and de-stoned pastes: Influence of the introduction of a heat exchanger on oil quality. Food Chemistry. 2006;**98**(4):797-805

[4] Amirante P, Clodoveo ML, Tamborrino A, Leone A, Dugo G. Oxygen concentration control during olive oil extraction process: A new system to emphasize the organoleptic and healthy properties of virgin olive oil. Acta Horticulturae. 2008;**949**:473-480

[5] Amirante P, Clodoveo ML,

[6] Amirante P, Clodoveo ML, Tamborrino A, Leone A, Paice AG. Influence of the crushing system: Phenol content in virgin olive oil produced from whole and de-stoned pastes. In: Olives and Olive Oil in Health and Disease Prevention. London, UK; 2010. pp. 69-76

London, UK; 2010. pp. 85-93

Tamborrino A, Leone A. A new designer malaxer to improve thermal exchange enhancing virgin olive oil quality. Acta Horticulturae. 2008;**949**:455-462

[7] Amirante P, Clodoveo ML, Leone A, Tamborrino A, Patel VB. Influence of different centrifugal extraction systems on antioxidant content and stability of virgin olive oil. In: Olives and Olive Oil in Health and Disease Prevention.

Energy. 2016;**89**:411-421

**References**

*Does the Introduction of Ultrasound in Extra-Virgin Olive Oil Extraction Process Improve… DOI: http://dx.doi.org/10.5772/intechopen.81666*

#### **References**

*Technological Innovation in the Olive Oil Production Chain*

**30**

**Author details**

Maria Lisa Clodoveo1

of Bari, Bari, Italy

provided the original work is properly cited.

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

and Riccardo Amirante3

\*, Filomena Corbo2

\*Address all correspondence to: marialisa.clodoveo@uniba.it

1 Interdisciplinary Department of Medicine, University of Bari, Bari, Italy

2 Department of Pharmacy-Pharmaceutical Science, University of Bari, Bari, Italy

3 Department of Mechanics, Mathematics and Management, Polytechnic University

[1] Amirante R, Clodoveo ML, Distaso E, Ruggiero F, Tamburrano P. A trigeneration plant fuelled with olive tree pruning residues in Apulia: An energetic and economic analysis. Renewable Energy. 2016;**89**:411-421

[2] Restuccia D, Clodoveo ML, Corbo F, Loizzo MR. De-stoning technology for improving olive oil nutritional and sensory features: The right idea at the wrong time. Food Research International. 2018;**106**:636-646

[3] Amirante P, Clodoveo ML, Dugo G, Leone A, Tamborrino A. Advance technology in virgin olive oil production from traditional and de-stoned pastes: Influence of the introduction of a heat exchanger on oil quality. Food Chemistry. 2006;**98**(4):797-805

[4] Amirante P, Clodoveo ML, Tamborrino A, Leone A, Dugo G. Oxygen concentration control during olive oil extraction process: A new system to emphasize the organoleptic and healthy properties of virgin olive oil. Acta Horticulturae. 2008;**949**:473-480

[5] Amirante P, Clodoveo ML, Tamborrino A, Leone A. A new designer malaxer to improve thermal exchange enhancing virgin olive oil quality. Acta Horticulturae. 2008;**949**:455-462

[6] Amirante P, Clodoveo ML, Tamborrino A, Leone A, Paice AG. Influence of the crushing system: Phenol content in virgin olive oil produced from whole and de-stoned pastes. In: Olives and Olive Oil in Health and Disease Prevention. London, UK; 2010. pp. 69-76

[7] Amirante P, Clodoveo ML, Leone A, Tamborrino A, Patel VB. Influence of different centrifugal extraction systems on antioxidant content and stability of virgin olive oil. In: Olives and Olive Oil in Health and Disease Prevention. London, UK; 2010. pp. 85-93

[8] Clodoveo ML. Malaxation: Influence on virgin olive oil quality. Past, present and future—An overview. Trends in Food Science & Technology. 2012;**25**(1):13-23

[9] Clodoveo ML, Hbaieb RH, Kotti F, Mugnozza GS, Gargouri M. Mechanical strategies to increase nutritional and sensory quality of virgin olive oil by modulating the endogenous enzyme activities. Comprehensive Reviews in Food Science and Food Safety. 2014;**13**(2):135-154

[10] Gómez Herrera C. Matter transfer during virgin olive oil elaboration. Grasas y Aceites. 2007;**58**(2): 194-205

[11] Clodoveo ML, Dipalmo T, Crupi P, Durante V, Pesce V, Maiellaro I, et al. Comparison between different flavored olive oil production techniques: Healthy value and process efficiency. Plant Foods for Human Nutrition. 2016;**71**(1):81-87

[12] De Luca M, Restuccia D, Clodoveo ML, Puoci F, Ragno G. Chemometric analysis for discrimination of extra virgin olive oils from whole and stoned olive pastes. Food Chemistry. 2016;**202**:432-437

[13] Clodoveo ML, Dipalmo T, Schiano C, La Notte D, Pati S. What's now, what's new and what's next in virgin olive oil elaboration systems? A perspective on current knowledge and future trends. Journal of Agricultural Engineering. 2014;**45**(2):49-59

[14] Clodoveo ML, Camposeo S, De Gennaro B, Pascuzzi S, Roselli L. In the ancient world, virgin olive oil was called "liquid gold" by Homer and "the great healer" by Hippocrates. Why has this mythic image been forgotten? Food Research International. 2014;**62**:1062-1068

[15] Roselli L, Clodoveo ML, Corbo F, De Gennaro B. Are health claims a useful tool to segment the category of extra-virgin olive oil? Threats and opportunities for the Italian olive oil supply chain. Trends in Food Science & Technology. 2017;**68**:176-181

[16] Roselli L, Cicia G, Cavallo C, Del Giudice T, Carlucci D, Clodoveo ML, et al. Consumers' willingness to buy innovative traditional food products: The case of extra-virgin olive oil extracted by ultrasound. Food Research International. 2018;**108**:482-490

[17] Clodoveo ML. New advances in the development of innovative virgin olive oil extraction plants: Looking back to see the future. Food Research International. 2013;**54**(1):726-729

[18] Clodoveo ML. An overview of emerging techniques in virgin olive oil extraction process: Strategies in the development of innovative plants. Journal of Agricultural Engineering. 2013;**44**(2s):297-305

[19] Clodoveo ML, Dipalmo T, Rizzello CG, Corbo F, Crupi P. Emerging technology to develop novel red winemaking practices: An overview. Innovative Food Science & Emerging Technologies. 2016;**38**:41-56

[20] Clodoveo ML, Durante V, La Notte D. Working towards the development of innovative ultrasound equipment for the extraction of virgin olive oil. Ultrasonics Sonochemistry. 2013;**20**(5):1261-1270

[21] Clodoveo ML, Hbaieb RH. Beyond the traditional virgin olive oil extraction systems: Searching innovative and sustainable plant engineering solutions. Food Research International. 2013;**54**(2):1926-1933

[22] Clodoveo ML, Durante V, La Notte D, Punzi R, Gambacorta G. Ultrasoundassisted extraction of virgin olive oil to improve the process efficiency.

European Journal of Lipid Science and Technology. 2013;**115**(9):1062-1069

[23] Clodoveo ML, Camposeo S, Amirante R, Dugo G, Cicero N, Boskou D. Research and innovative approaches to obtain virgin olive oils with a higher level of bioactive constituents. In: Olive and Olive Oil Bioactive Constituents. Urbana, Illinois; 2015. pp. 179-215

[24] Clodoveo ML, Moramarco V, Paduano A, Sacchi R, Di Palmo T, Crupi P, et al. Engineering design and prototype development of a full scale ultrasound system for virgin olive oil by means of numerical and experimental analysis. Ultrasonics Sonochemistry. 2017;**37**:169-181

[25] Amirante R, Distaso E, Tamburrano P, Paduano A, Pettinicchio D, Clodoveo ML. Acoustic cavitation by means ultrasounds in the extra virgin olive oil extraction process. Energy Procedia. 2017;**126**:82-90

**33**

Section 3

Health Effects
