Effects of chitosan on the gel properties of salt-soluble meat proteins from silver carp

Chitosans (CHI) with different degree of deacetylation (DD) (60.5%, 65.4%, 70.8%, 77.3%, 86.1%) and different molecular weight (MW) (299, 410, 600, 706, 880 kDa) were obtained. Heat-induced composite gels were prepared from 4% salt-soluble meat proteins (SSMP) with chitosans at 0.6 mol/L NaCl, pH 7.0. Penetration forces and storage modulus of SSMP–CHI composite gels increased proportionally with increasing amount of molecular weight. Gel containing chitosan with DD 77.3% exhibited the highest penetration force and storage modulus. The SEM observations showed that SSMP–CHI incorporated gels were compact and fine compared with that of SSMP. Chemical forces involved in SSMP–CHI composite gels were investigated by determining the effects of NaCl, urea, propylene glycol, and 2-MeSH on penetration forces. Results of these studies demonstrated that interaction between CHI and SSMP contributed to the enhancement of texture of the SSMP–CHI composite gels by electrostatic interactions and hydrogen bonds.