Forces Involved in Mixed Pork Myofibrillar Protein and Calcium Alginate Gels

Calcium alginate (CA) gels containing pork myofibrillar protein (MP) were prepared at pH 5.2-6.2, at 25 and 92 °C. Molecular interactions in CA/MP composite gels were examined by determining the effects of 5 M urea, 0.5 M NaCl, 0.5 M NaSCN, 10% propylene glycol, and 0.2 M 2-mercaptoethanol on gel strength. CA gel strength was increased by MP at pH 5.2-S.5 and destabilized above pH 5.5. Heating at 92 °C generally promoted CA gelation. CA/MP gels were markedly destabilized by NaCl and NaSCN and, to a lesser extent, by urea and propylene glycol but were slightly stabilized by 2- mercaptoethanol at 92 °C. These results suggest that electrostatic interactions and hydrogen bonds were the major forces involved in the CA/MP gel systems.