Delipidated egg yolk protein modification by controlled enzymatic hydrolysis and its preliminary application

• 1、The Key labtory of Food Science and Technology,School of Food Science and Technology,Jiangnan University,JiangSu WuXi 214122

Abstract：Delipidated egg yolk protein(EYP) is produced as a co-product of egg yolk lecithin extraction.This EYP is expected to have poor functionality because of protein denaturation caused by organic solvents treatment during lecithin extraction.Delipidated egg yolk protein(EYP) was controlled hydrolyzed by three different sources of enzyme,and the effect of hydrolysis on the functional properties of EYP as well as the analysis of phosphorus content was systematically investigated.Then,EYP was divided into the soluble fractions and the insoluble fractions used in different fields,respectively.The results showed that the slight hydrolysis could improve the solubility,foaming capacity and foam stability significantly,while sightly increase the emulsification capacity.As for the modification effect,the three kinds of enzymes could be ranked according to the arrangement from high to low as follows:plant proteases＞ animal proteases＞microbe-proteases.Phosphorus content analysis showed that the trypsin hydrolysis sediment phosphorus content decline significantly, and sediments after the rest protease treatment little change.Compare integratedly, choose papain modified hydrolysate for application.Application results showed that the soluble fractions could partly replace egg white make angel food cake because of its high foamability.Substitution rate is less than 10% could make cake which similar with that made by 100% egg white protein.After phosphorus content analysis,the insoluble fractions was proved can be used as the source of phosvitin phosphopeptides.

Keywords： Delipidated egg yolk protein Controlled Enzymatic Hydrolysis Foaming Properties Angel Cake