Abstract:Gelling properties of silver carp surimi as influenced by vacuum and calcium ion concentration were investigated for the production high-quality surimi products. As concentration of calcium chloride increased, breaking forces of surimi gels prepared under atmospheric pressure fluctuated, which increased and then decreased twice (p<0.05).The calcium ion concentrations corresponding to the two peaks were 20 mmol/kg and 40 mmol/kg. Cross-linking degree of surimi gels increased from 18.08% to 30.98%, and then decreased gradually after 30mmol/kg and finally reached the minimum value of 14.54%. Microstructure was in irregular form firstly, and then changed to a continuous network followed by scattered aggregations. Under vacuum chopping, changes in characteristic values of surimi gel, including breaking force and cross-linking degree, were similar to those under atmospheric pressure. However, calcium ion concentrations corresponding to the peaks and turnover were lower by 10 mmol/kg. Under both chopping conditions, water holding capacities of surimi gels decreased from 80.74% and 82.27% to 62.09% and 67.23%, respectively. And their whiteness were increased from 79.11 and 79.10 to 83.80 and 83.15, respectively. Results indicated that vacuum changed the gelling properties of surimi by decreasing calcium ion concentrations.
