Free-fatty acid profile obtained by enzymatic solvent-free hydrolysis of sunflower and soybean lecithin

MARÍA C. PENCI; DIANA T. CONSTENLA; AMALIA A. CARELLI

FOOD CHEMISTRY

ELSEVIER SCI LTD

Lugar: UK; Año: 2010 vol. 120 p. 332 - 338

0308-8146

Abstract: The free-fatty-acid profile of sunflower and soybean lecithins generated by enzymatic hydrolysis was determined by capillary gas chromatography using the internal standard method. This procedure involves the previous lipid extraction, clean-up and fatty-acid methyl-esters preparation. Different conventional methods commonly employed to calculate the hydrolysis degree in both substrates were compared. The fatty-acid profile of sunflower and soybean phospholipids and its initial acidity composition were chromatographically determined. Results from recovery studies were satisfactory (98 % and 108% for soybean and sunflower, respectively). The effect of temperature (50ºC and 60ºC) and pH conditions (pH=7and pH=8) on lecithin hydrolysis degree was evaluated, being temperature the most affecting parameter. The profile of the fatty acids liberated after hydrolysis depended on both the enzyme and the pH of reaction mixture. Finally, the chromatographic methodology employed in this paper may be useful to study the lecithin enzymatic modification in order to produce emulsifiers with specific characteristics.