Effects of ionic strength on chemical forces and functional properties of heat-induced myofibrillar protein gel

Abstract

Effects of ionic strength on chemical forces and functional properties of heat-induced myofibrillar protein gel were investigated. The decrease of total sulfhydryl groups suggested that more disulfide bonds formed with the increase of ionic strength. The increase of surface hydrophobicity and normalized intensity of 760 cm-1 band of Raman spectra indicated that higher ionic strength strengthened hydrophobic interactions. The decrease of normalized ratio of I850/I830 and absolute value of zeta potential indicated that higher ionic strength weakened hydrogen bonds and electrostatic interactions. The storage modulus (G'), hardness and water holding capacity (WHC) all increased significantly with the increase of ionic strength from 0.2 - 0.6 ( p < 0.05). The enhancement of functional properties at higher ionic strength was achieved by strengthening attractive forces and weakening repulsive forces.