Free Fatty Acid distribution in vegetable lecithin

PENCI, C.; CONSTENLA, D.; CARELLI, A.

Seatle USA

Congreso; 99th AOCS Annual Meeting & Expo; 2008

AOCS

 FREE-FATTY ACID DISTRIBUTION OF VEGETABLE LECITHINS OBTAINED BY SOLVENT-FREE ENZYMATIC MODIFICATION                        Cecilia Penci*; Diana T. Constenla; Amalia A. Carelli   The free-fatty acid (FFA) obtained by enzymatic hydrolysis of soybean- and sunflower- lecithin employing A1 and A2 phospholipases (PLA1, PLA2) were quantified by capillary gas chromatography using lauric acid as internal standard. The analytical methodology involves solvent extraction, clean-up and FFA transmethylation. At 50°C and 60°C de-oiled lecithins were modified in solvent-free reaction media of pH 7 and pH 8 with 20 mg lecithin/mL. In all experiences, the reaction conversion augmented with temperature increase. The FFA profiles were affected by the pH of the reaction medium and the enzyme type. When the reactions were performed with PLA1 at pH 7, the main fatty acids released were C16:0, C20:0, C14:0. However, C22:0 and C24:0 were also detected at pH 8. In contrast, experiences with PLA2 presented C18:2 as the main FFA in both substrates and all reaction conditions. With this enzyme, C16:1 and C22:1 were also liberated at pH 8, being notable the presence of C18:3 for soybean lecithin.  This study lets us know the influence of the enzyme, the substrate, the pH and the temperature on fatty-acid liberation. In addition, this paper is useful so as to infer the lysophospholipid fatty-acid composition, which has influence on their emulsifying  properties.