Insight into the impacts of Jinhua ham processing conditions on cathepsin B activity and conformation changes based on molecular simulation

To produce the high quality products and improve the stability of Jinhua hams, the activities of cathepsins and their correlation with processing parameters were explored. The effect of heat treatment on the structure of cathepsin B, together with potential of hydrogen and NaCl concentration, were investigated. At 45 °C, the activity of cathepsin B was maximum and it decreased rapidly at high temperature. The decrease on sulfhydryl group content indicated that the enzyme activity varied due to the breaking of disulfide bond in molecule. Infrared spectroscopy indicated that the secondary structure of cathepsin B had altered. Meanwhile, the root mean squared deviation and the root mean square fluctuation curves reflected that the cathepsin B vitality was in a decline under high temperature. In addition, in the presence of 0.6 mol ⋅ L−1 NaCl, lots of conformational changes were evidenced. Under acidic conditions (pH = 6), there were more formed hydrogen bonds, and the hydrogen bonding interactions became stronger. Simulation results contributed to providing an important theoretical basis for understanding the roles of processing parameters on the quality control of Jinhua ham.