Physico-chemical and gel properties of heat-induced pasteurized liquid egg white gel: effect of alkyl chain length of alcohol

Abstract

The influence of alcohols with different alkyl chain length (methanol, ethanol and propanol) on the physicochemical properties (turbidity, surface hydrophobicity, exposed and total free sulfhydryl groups, denaturation temperature; Tm) of pasteurized liquid egg white (PLEW), including gel properties (gel hardness and expressible liquid) and microstructure of heat-induced PLEW gel prepared at 75°C were studied. The results showed that alkyl chain length of alcohol and alcohol concentration had no impact on the total free sulfhydryl groups, but significantly increased the turbidity, surface hydrophobicity, exposed free sulfhydryl groups, gel hardness and expressible water. Increase the alkyl chain length of alcohol also significantly decreased the Tm and the total enthalpy change during heat-induced gelation of PLEW. Addition of 5% alcohol altered the microstructure of the PLEW gels in an alkyl chain length dependent manner.