N. Matsudomi et al., CHARACTERISTICS OF HEAT-INDUCED TRANSPARENT GELS FROM EGG-WHITE BY THE ADDITION OF DEXTRAN SULFATE, Journal of agricultural and food chemistry, 45(3), 1997, pp. 546-550
Heat-induced egg white gels containing polysaccharides were formed at
pH 6.5, and the physicochemical properties were investigated. The hard
ness, water-holding capacity, and transparency of egg white gel marked
ly increased in the presence of dextran sulfate (DS) at a weight ratio
of 0.05 to the protein. The effects were not observed by the addition
of dextran (DX). Scanning electron microscopy showed that a very fine
network structure had been formed in the gel containing DS. The actio
n of DS on heat gelation of egg white,appeared mainly due to chemical
interactions rather than physical entanglement. Dilute solutions of eg
g white alone and egg white containing DX formed insoluble aggregates
by protein interactions through disulfide cross-links during heating.
From SDS-PAGE analysis with 2-mercaptoethanol, the insoluble aggregate
s consisted of ovalbumin, ovotransferrin, and lysozyme. The addition o
f DS inhibited formation of insoluble aggregates in egg white solution
during heating. The inhibitory effect of DS would be ascribed to the
formation of firmer and transparent egg white gels.