**1. Introduction**

300 Food Industrial Processes – Methods and Equipment

Zeng, Y.; Zhang, X.; Guan, Y. & Yuanxia, S. (2011). Characteristics and Antioxidant Activity

8146.

294

L-threonine/L-serine. *Food Chemistry*, Vol.119, No.1, March, pp.214–219, ISSN 0308-

of Maillard Reaction Products from Psicose-Lysine and Fructose-Lysine Model Systems. *Journal of Food Science*, Vol.76, No.3, April, pp.398-403, ISSN 0022-1147.

> The main citrus producing countries according to FAO (2008) are China, Brazil and the United States, followed by Mexico, Spain and Italy. However, by species, Brazil is the first world producer of oranges and lemons by conventional tillage, followed by the United States, while China stands out in the production of tangerines.

> In Brazil, the acid lime cv. *Tahiti* (*Citrus latifolia* Tanaka), also known as *Tahiti* lemon, is regarded as one of the commercially most important citric fruits, occupying over 30,000 hectares of cultivated area (Fig.1) (Barros, 1986).

> The acid lime is used raw or in the form of juice, especially as an ingredient in the composition of blends to enhance the flavor of beverages (FAO, 2008).

Fig. 1. Leaves and fruits of *Citrus latifolia* Tanaka, cv. Tahiti (Bom Jesus Farm, São Paulo, July, 2009).

Organic Acid Lime (*Citrus Latifolia* Tanaka) Clarified by Microfiltration 303

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antioxidant, anti-inflammatory, antimicrobial and anticancer activities (Rodrigo et al, 2011;

The physiological role of phenolic compounds can be more easily understood if one takes into account that *in vitro* the antioxidant capacity of these substances is related not only to their chemical structures, but also depends upon the type and polarity of the solvent used for the extraction, the isolation process and purity of the compounds, as well as on the substrate to be protected by the antioxidant, and if an aqueous or lipophylic assay system is

Ultrafiltration (UF) and microfiltration (MF) processes have been used by food industries for the clarification, concentration, and cold sterilization of liquids, producing food without chemical additives, with low power consumption, providing alternative products with nutritional quality and agreeable flavor (Carvalho et al., 2008; Koroknai et al., 2008; Cassano

Investigation of the nutritional and sensory post-process quality is required to fulfill the needs of the consumer market for clarified juices, because several substances with nutritional value such as vitamins and minerals, among others, cannot be recovered in the clarified juice or even be retained in the concentrated pulp, or on the surface or inside the membrane pores after UF and MF of juices, with or without prior enzymatic treatment

As well as any other industrial food processing technology, membrane separation processes have several advantages and disadvantages (Habert et al., 2003). The most important drawback is "fouling", a key event in UF and MF processes that can affect economic and commercial viability of a system, since it reduces productivity and useful life of the membrane (Nilsson, 1990). Advantages of membrane processes are increased yields of clarified juices, possibility of operation in one step, lower operational time, operation at room temperature (avoiding food degradation), simple and fast cleaning system, as well as preservation of nutritional and sensory characteristics of foods (Castro et al., 2007; Vaillant

The aim of this study was to determine the total polyphenol content in biodynamic organic

A total of 113 kg of biodynamic organic acid lime (*Citrus latifolia* Tanaka), cultivar *Tahiti*, 2009 crop, (certified by IBD/IFOAM - Federación Internacional de Movimientos de Agricultura Orgánica) and 58.40 kg of conventionally cultivated acid lime, 2009 crop, were supplied by Bom Jesus Farm, located in Santa Rita do Passa Quatro, São Paulo, Brazil. After selection, whole, non-injured fruits were weighed and sanitized by immersion in chlorinated water (100 ppm for 10 min.) and washed. The juice was extracted in a semiindustrial multiprocessor (Konik, Class 700 model, São Paulo, Brazil), sieved, packed in PVC

Before each MF process, the membrane water permeability was measured at transmembrane pressures of 0.5, 1.0 and 2.0 Bar, respectively, to verify its recovery, according to the

Beer et al, 2005).

et al., 2001).

**2.1 Materials** 

following formula:

**2. Material and methods** 

to be used (Giada, 2005).

et al., 2004; Girard, & Fukumoto, 2000).

(Koroknai et al., 2008; Cianci et al., 2005; Carvalho et al., 1998).

acid lime juice clarified by membrane processes of microfiltration.

containers and stored at – 15 °C, until processing and analyses.

**2.2 Water permeability and juice recovery (%)** 

According to the Secretary of Agricultural Protection (SAP, 1999), the organic system adopts technologies that optimize natural resources, including ecological, biodynamic, natural, sustainable, regenerative, organic and agroecological crops.

So far, the most accurate and reliable system that allows the consumer to determine if a food has been produced by organic or biodynamic organic cultivation is the quality seal provided by national and international entities, such as the Biodynamic Institute (IBD), an organization established in 1991 that develops certification of organic and biodynamic products (Darolt, 2003).

The organic quality seal is an indication that the food was produced and processed in accordance with the guidelines and standards of organic farming, resulting in a positive agronomic quality when compared to conventionally grown food, along with safety and reliability for the consumers that the products have not been subjected to ionizing radiation and have no transgenic or genetically modified organisms (GMOs) in their composition. Therefore, cultivation (without pesticides, fertilizers or chemicals) plus the quality certificate of the Biodynamic Institute (IBD) characterize biodynamic agriculture (IBD, 2009; Darolt, 2003).

The citrus flavor and aroma are pleasant, and in its composition are essential nutrients and micronutrients such as vitamins and minerals, and fiber (Pellegrini et al., 2003; Morton et al., 2000). Vitamin C and phenolic compounds present in acid lime have the ability to capture free radicals, having an important role in its antioxidant activity (Dhuique-Mayer, 2005; Harbone & Williams, 2000).

Polyphenols are a heterogeneous group, composed of several classes of substances with antioxidant properties that are found in different foods and drinks. Typical compounds that possess antioxidant activity include phenols, phenolic acids and their derivatives, carotenoids, flavonoids (anthocyanins and anthoxantins), tocopherols, phospholipids, amino acids, phytic acid, ascorbic acid and sterols (Roesler et al., 2008).

The first studies on determination of total phenolics were published by Folin & Ciocalteau (1927), Swain & Hillis (1959), Singleton & Rossi (1965), and Fantozzi & Montedoro (1978). Different methods can be employed to determine the total content of phenolic compounds in foods and plants. The most utilized procedures employ the *Folin-Ciocalteau* reagent, in which the mixture of phosphowolframic and phosphomolybdic acids, in alkaline media, is reduced by oxidizing phenolic compounds, giving rise to blue wolframium (W8O23) and molybdenum (Mo8O23) oxides (Mirsaeedghazi et al, 2010; Mezadri et al, 2008; Kuskoski et al*.*, 2006).

Some citric fruits such as acerola, orange and lemon contain high concentrations of ascorbic acid, while certain flavonoids such as anthocyanins, flavonols and flavones predominate in strawberry, mulberry and açaí (Cordenunsi et al., 2005; Pozo-Insfran et al., 2004; Assis et al., 2001).

Jardini & Mancini-Filho (2007) evaluated antioxidant activity of different extracts from the pulp and seeds of rum, and found that the fruit showed high antioxidant activity due to the presence of phenolic and reducing compounds. Water extracts from the pulp and seeds were the most effective regarding antioxidant activity.

Santos et al. (2008) showed that anthocyanins and total phenolics had a positive and significant correlation with the high antioxidant capacity of açaí pulps.

Beneficial health effects, especially a significant decrease on the incidence of chronic and degenerative deseases, have been attributed to ascorbic acid and phenolic constituents of fruits, vegetables, cereals, tea and wine. Epidemiological, clinical and *in vitro* studies indicate relationships between dietary polyphenols and certain biological effects, such as antioxidant, anti-inflammatory, antimicrobial and anticancer activities (Rodrigo et al, 2011; Beer et al, 2005).

The physiological role of phenolic compounds can be more easily understood if one takes into account that *in vitro* the antioxidant capacity of these substances is related not only to their chemical structures, but also depends upon the type and polarity of the solvent used for the extraction, the isolation process and purity of the compounds, as well as on the substrate to be protected by the antioxidant, and if an aqueous or lipophylic assay system is to be used (Giada, 2005).

Ultrafiltration (UF) and microfiltration (MF) processes have been used by food industries for the clarification, concentration, and cold sterilization of liquids, producing food without chemical additives, with low power consumption, providing alternative products with nutritional quality and agreeable flavor (Carvalho et al., 2008; Koroknai et al., 2008; Cassano et al., 2004; Girard, & Fukumoto, 2000).

Investigation of the nutritional and sensory post-process quality is required to fulfill the needs of the consumer market for clarified juices, because several substances with nutritional value such as vitamins and minerals, among others, cannot be recovered in the clarified juice or even be retained in the concentrated pulp, or on the surface or inside the membrane pores after UF and MF of juices, with or without prior enzymatic treatment (Koroknai et al., 2008; Cianci et al., 2005; Carvalho et al., 1998).

As well as any other industrial food processing technology, membrane separation processes have several advantages and disadvantages (Habert et al., 2003). The most important drawback is "fouling", a key event in UF and MF processes that can affect economic and commercial viability of a system, since it reduces productivity and useful life of the membrane (Nilsson, 1990). Advantages of membrane processes are increased yields of clarified juices, possibility of operation in one step, lower operational time, operation at room temperature (avoiding food degradation), simple and fast cleaning system, as well as preservation of nutritional and sensory characteristics of foods (Castro et al., 2007; Vaillant et al., 2001).

The aim of this study was to determine the total polyphenol content in biodynamic organic acid lime juice clarified by membrane processes of microfiltration.
