ENZYMATIC-HYDROLYSIS OF OAT AND SOYA LECITHIN - EFFECTS ON FUNCTIONAL-PROPERTIES

Enzymatic hydrolysis of oat and soy lecithins and its effects on the f unctional properties of lecithins were investigated. The phospholipase used was most efficient at low enzyme and substrate concentrations, M ore fatty acids were released from soy lecithin than from oat lecithin . The maximum degree of hydrolysis was 760 mu mol free fatty acids per gram soy lecithin and 170 mu mol free fatty acids per gram oat lecith in. On the basis of the total carbohydrate and phosphorus contents in the polar fractions of the lecithins, oat lecithin contained more glyc olipids and less phospholipids than soy lecithin. With regard to funct ional properties, the stability of oil in water emulsions was enhanced by hydrolyzed soy lecithin and by crude and hydrolyzed oat lecithins, but only hydrolyzed soy lecithin prevented the recrystallization of b arley starch. The dissociation enthalpy of amylose-lipid complex (AML- complex) was significantly higher when hydrolyzed soy lecithin was pre sent. Hydrolyzed oat lecithin slightly affected the dissociation entha lpy of AML complex. The other lecithins had no effect on recrystalliza tion or dissociation enthalpies in the barley-starch matrix.