Effects of pressure level and sodium chloride contents on the water-holding capacity of rabbit myosin gel and its physiochemical properties and structural changes during gelling

By using myosin extracted from rabbit skeletal muscles as experimental material, which contained different amounts of sodium chloride (1.0%, 1.5%, 2.0%)and subjected to various levels (100, 200, 300 MPa)of high pressure treatment (9 min, 25℃)before heating. The effects of pressure levels and sodium chloride contents on the rheological properties and conformational structures of protein during gelling as well as the water characteristics of formed gel were investigated. The water holding capacity, water distribution and the microstructure of gel as well as the storage modulus, surface hydrophobicity, reactive sulfhydryl contents and the secondary structures of protein during heating were measured. Unpressurized myosin with 2% sodium chloride content was set as control. The results showed that rapid exposure of hydrophobic and sulfhydryl groups happened in 100 and 200 MPa treated myosin with 1% sodium chloride content between 40 and 55℃ and the proportion of α-helix structures decreased simultaneously (p<0.05). All these phenomenon indicated that its higher rate of denaturation allowed sufficient unfolding of myosin during heating, which resulted in higher water holding capacity and final storage modulus as well as better microstructure of gel than others. It can provide valuable reference for the broader application of high-pressure technology to industry.