**5.** *Olive oil* **traceability**

Food traceability implies the control of the entire chain of food production and marketing, allowing the food to be traced through every step of its production back to its origin. The verification of food traceability is necessary for the prevention of deliberate or accidental mislabeling, which is very important in the assurance of public health. Thus, several regulations provide the basis for the assurance of a high level of protection of human health and consumers' interest in relation to food.

In the case of *olive oil*s, the increase in the demand for high-quality *olive oil*s has led to the appearance in the market of *olive oil*s elaborated with specific characteristics. They include oils of certain regions possessing well-known characteristics, that is, *olive oil*s with a denomination of origin, or with specific olive variety composition, that is, coupage or monovarietal *olive oil*s. *Olive oil*s obtained from one genetic variety of olive or from several different varieties are called monovarietal or coupage, respectively. Monovarietal *olive oil*s have certain specific characteristics related to the olive variety from which they are elaborated (Montealegre et al., 2010). However, coupage *olive oil*s are obtained from several olive varieties to achieve a special flavor or aroma.

The appearance of denominations and protected indications of origin has promoted the existence of oils labeled according to these criteria. Regulation 2081/92 (2) created the systems known as Protected Designation of Origin (PDO), Protected Geographical Indication (PGI) and the ''Traditional Speciality Guaranteed" (TSG) to promote and protect food products (Table 2).


\*Council Regulation (EC) 510/2006, March 20, 2006.

Table 2. General regimen for food and certain other agricultural products based on Regulation 510/2006\*

For example, an *olive oil* with a PDO denomination requires meeting precise definition of several parameters such as cultivar, geographical origin, agronomic practice, production

Greece produced 32, 28 and 13.5 percent of the world's *olive oil*, respectively. However, the recent expansion of the *olive oil* industry and significant contribution to the global *olive oil* market by several other countries, such as Australia and the United States, may lead to

Food traceability implies the control of the entire chain of food production and marketing, allowing the food to be traced through every step of its production back to its origin. The verification of food traceability is necessary for the prevention of deliberate or accidental mislabeling, which is very important in the assurance of public health. Thus, several regulations provide the basis for the assurance of a high level of protection of human health

In the case of *olive oil*s, the increase in the demand for high-quality *olive oil*s has led to the appearance in the market of *olive oil*s elaborated with specific characteristics. They include oils of certain regions possessing well-known characteristics, that is, *olive oil*s with a denomination of origin, or with specific olive variety composition, that is, coupage or monovarietal *olive oil*s. *Olive oil*s obtained from one genetic variety of olive or from several different varieties are called monovarietal or coupage, respectively. Monovarietal *olive oil*s have certain specific characteristics related to the olive variety from which they are elaborated (Montealegre et al., 2010). However, coupage *olive oil*s are obtained from several

The appearance of denominations and protected indications of origin has promoted the existence of oils labeled according to these criteria. Regulation 2081/92 (2) created the systems known as Protected Designation of Origin (PDO), Protected Geographical Indication (PGI) and the ''Traditional Speciality Guaranteed" (TSG) to promote and protect

**General regimen Origin Characteristics Restriction** 

Table 2. General regimen for food and certain other agricultural products based on

For example, an *olive oil* with a PDO denomination requires meeting precise definition of several parameters such as cultivar, geographical origin, agronomic practice, production

Quality essentially or exclusively due to a particular geographical area

Slightly less strict; food reputation of a product from a given region is sufficient

Produced, processed and prepared in a given geographical area

One of the stages of production, processing, or preparation takes place in the area

In that region, specific place, or country

In that region, specific place, or country

\*Council Regulation (EC) 510/2006, March 20, 2006.

stabilization of the market in the near future.

and consumers' interest in relation to food.

olive varieties to achieve a special flavor or aroma.

**5.** *Olive oil* **traceability** 

food products (Table 2).

Protected Designation of Origin (PDO)

Protected Geographical Indication (PGI)

Regulation 510/2006\*

technology, and organoleptic qualities (Gimenez et al., 2010), and all of these parameters have to be investigated to study its traceability and to certify its quality. Among the abovementioned factors, the two first are the most important (Montealegre et al., 2010).

Additionally, a Database of Origin and Registration (DOOR) was created to support these denominations (Montealegre et al., 2010). Based on the report of the *International Olive Council* (http://www.internationaloliveoil.org) gave the world production of *olive oil* in 2008/2009 as 2,669.5 million tons and it consumption for the same period as 2,831.5 million tons. It is quite clear that some of the *olive oil* sold has been mislabeled. *Olive oil* is priced from \$13–105 for 500 mL where as canola oil and sunflower oils available from less than \$1–10 for 500 mL.

The introduction of certifications of origin and quality for virgin *olive oil* as PDO makes necessary the implementation of traceability procedures. It seems that DNA analysis to be a promising approach to this problem, since it is less influenced by environmental and processing conditions in respect to other methods (i.e.; metabolites).

Any research dealing with *olive oil* traceability is focused on investigating the botanical or geographical origin. However, the concept of geographical traceability, in which the objective is the geographical location of the olive tree, is slightly different from the concept of botanical traceability, in which the olive used for the *olive oil* production is the aim. In both cases, the selection of the markers (compounds with discriminating power) to be studied is complicated because the composition of extra virgin *olive oil*s is the result of complex interactions among olive variety, environmental conditions, fruit ripening, and oil extraction technology (Araghipour et al., 2008).

## **5.1 Traceability to the botanical origin**

The verification of the cultivars employed to produce an *olive oil* sample may contribute to address the oil origin. This fact may have commercial interest in the case of monovarietal *olive oil*s or *olive oil*s with PDO because these high-quality *olive oil*s may be adulterated by other oils of lower quality, using anonymous or less costly cultivars (Breton, 2004).

As the quality of an *olive oil* depends on the olive variety from which it is elaborated, the production of *olive oil*s from certain varieties has increased (Sanz-Cortes et al., 2003). The olive variety selection is based on its adaptation to different climatic conditions and soils. In addition, whereas some cultivars are characteristic of a given zone, others can be found in several countries (Japon-Lujan et al., 2006). As a consequence, one olive variety can be cultivated and nominated in a different way in distinct geographical locations, which makes the differentiation of olive varieties in *olive oil*s quite complex. (Montealegre et al., 2010)

Traditionally, differentiation among olive cultivars has been supported by numerous morphological (study of the form or shape) and pomological (the development, cultivation, and physiological studies of fruit trees) traits. Unfortunately, morphological traits have been difficult to evaluate, are affected by subjective interpretations, and are severely influenced by the environment and plant developmental stage (Sanz-Cortes et al., 2003). Nowadays, several efforts have been focused on the investigation of one or several compounds present in *olive oil*s usable to differentiate olive varieties (Montealegre et al., 2010). Compositional markers (substances that take part of the composition of the olive oils) include major and minor components. Major, (sterols, phenolic compounds, volatile compounds, pigments,

Traceability of Origin and Authenticity of *Olive Oil* 171

these markers are highly affected by the environmental conditions, the fruit ripening, and

Molecular markers are investigated as a diagnostic tool for food authenticity and traceability of variety/type composition of complex food matrices in an increasing number of projects (Palmieri et al., 2004). DNA-based methods make an important contribution to protect high-

Significant amounts of DNA are present in *olive oil* obtained by cold pressing (Consolandi et al., 2008). However, the filtration process lowers DNA concentrations, which tend to disappear due to nuclease degradation (De la Torre et al., 2004; Muzzalupo et al., 2002). On the other hand, the length of storage after milling of the oil can affect the use of DNA as an analyte for molecular traceability. Pafundo et al., 2010 observed a significant decrease of quality of DNA extracted from olive oil, with a consequent loss of information a month later

Spaniolas et al. (2008b) has used lambda DNA as a marker to monitor the length of DNA fragments in olive oil during storage time when determined the varietal origin of olive oil. Lambda DNA is a linear molecule of approximately 50 kb, a length that probably resembles that of olive DNA present in olive oil. Based on the fact, PCR-based fingerprinting techniques, which require templates longer than 100 bp, might not be able to successfully amplify the target sequences from olive oil samples low in DNA content and stored for several months, they conduct their analyses. They have deduced the detection of polymorphic markers requiring DNA templates shorter than 100 bp might have a wider

In *olive oil*, once the barrier of DNA extraction has been overcome, several markers could be used to identify olive cultivars that made up a certain *olive oil*. (Consolandi et al., 2008)

DNA recovery methods from *olive oil* have been developed by many authors (Busconi et al. 2003; Doveri et al. 2006; Pasqualone et al. 2007; Consolandi et al. 2008). Several commercial kits, providing adapted protocols, were used in different works (Martins-Lopes et al. 2008; Spaniolas et al. 2008a; Ayed et al. 2009; Pafundo et al. 2010). All of these studies confirmed that the DNA of the cultivars is recoverable from extra virgin *olive oil*, but it has low quantity and quality. The first researches, carried out using genomic DNA extracted from drupes. That DNA had a good potential to amplify correctly using RAPDs markers (Cresti et al. 1997). By means of SCAR and AFLP markers, Busconi et al. (2003) were able to show that DNA recovered from *olive oil* had both organellar and nuclear origin. Pafundo et al. (2005) traced the cultivar composition of monovarietal *olive oil*s by AFLPs, suggesting that DNA extraction is the most critical step affecting the procedure. Pafundo et al. (2007), performed amplification of DNA isolated from *olive oil* using AFLPs. They have also developed some SCARs to amplify successfully the DNA extracted from *olive oil*. Using SSR analysis, Pasqualone et al. (2007) demonstrated that microsatellites are useful in checking the presence of a specific cultivar in a PDO oil, thus verifying the identity of the product. However, they obtained only the marker profile of the main cultivar in the oil: no signal was detected for the secondary varieties. Montemurro et al. (2008) analyzed ten virgin monovarietal *olive oil*s prepared in the laboratory by AFLP markers. They were able to

the extraction technology (Montealegre et al., 2010).

range of applications in DNA fingerprinting of olive oil.

**6. DNA-based markers** 

from olive oil production.

quality *olive oil*s.

hydrocarbons, and tocopherols, fatty acids and triglycerides, components may provide basic information on olive cultivars. Minor components, can provide more useful information and have been more widely used to differentiate the botanical origin of *olive oil*s (Montealegre et al., 2010).
