TOMAS Mabel Cristina
capítulos de libros
Antioxidant and emulsifying properties of modified sunflower lecithin by fractionation with ethanol-water mixtures
DARIO CABEZAS; ESTEFANIA GUIOTTO; BERND W. K. DIEHL; MABEL C. TOMÁS
InTech Eds. I. Muzzalupo
Lugar: Rijeka; Año: 2013; p. 589 - 602
Lecithins are a mixture of acetone insoluble phospholipids, containing mainly phosphatidyl?] choline (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidic acid (PA), and other minor substances such as carbohydrates and triglycerides [1-3]. The produc?] tion of sunflower oil in Argentina, is of utmost importance from an economic point of view . In this country, sunflower lecithin could represent an alternative to soybean lecithin be?] cause it is considered a non-GMO product, which is in accordance with the preference of some consumers . Lecithins, in native or modified state, are used in a wide range of industrial applications: di?] etetic, pharmaceutical, food, cosmetics, etc. This by-product of the oil industry represents a multifunctional additive for the manufacture of chocolate, bakery and instant products, margarine, mayonnaise, due to the characteristics of its phospholipids [6-8]. The introduction of changes in the relative concentration of the original phospholipid com?] position of lecithin can originate enriched fractions in certain phospholipids with different physicochemical and functional properties for diverse industrial purposes [9-11]. The fractionation process by ethanol or ethanol:water mixtures takes advantage of the dif?] ferent solubility of the phospholipids in this solvent. PC is readily soluble in ethanol where?] as PI and PA are virtually insoluble. Phosphatidylethanolamine can be found in both fractions. This process can be carried out alone or in combination with other techniques such as chromatography as a further purification step, especially for pharmaceutical, cosmetic and dietetic industry [12-13]. The main application of lecithin at the food industry is associated with its rol as emulsifying agent for dispersions or emulsions . Emulsions are thermodynamically unstable systems from a physicochemical point of view. In virtue of that, it is important to characterize their behaviour against different destabilization processes (flocculation, coalescence, creaming, etc.) . PC enriched fraction, due to its high PC/PE ratio and the lamellar phase structure of the PC at the interface between oil in water, is recognized to be a good oil-in-water (O/W) emulsifier [12,16,17]. On the other hand, PLs can contribute to an improvement of the oxidative stability of fats and oils. Various antioxidative mechanisms have been proposed for the phospholipid ac?] tions. For example, the amino functions of PC, PS, or PE, or the sugar moiety of PI have been shown to have metal-chelating properties and PC and PE presented a synergistic effect, with phenolic antioxidants such as tocopherols and flavonoids [18, 19]. The objective of this work was to evaluate the antioxidant and emulsifying properties of modified sunflower lecithins by fractionation with ethanol-water mixtures. In this sense, this study seeks to contribute to the food industry with useful information about developing tai?] lor-made surface-active emulsifiers.