Role of ultrasound and L-lysine/L-argnine in improving the physical stability of myosin-soybean oil emulsion

This work investigated the mechanisms underlying the combined effects of ultrasound and L-lysine/L-arginine on the physical stability of myosin-soybean oil emulsions (MSE). The results showed that compared with the individual treatments (ultrasound, L-lysine or L-arginine), the combined treatments (ultrasound and L-lysine, ultrasound and L-arginine) were more effective in decreasing creaming index and emulsion size, but increasing emulsifying activity index, emulsifying stability index and emulsion zeta-potential, and forming smaller and more uniform MSEs. Also, except that active sulfhydryls decreased in the following order: ultrasonic treatment > a combination of Arg and ultrasound approximate to a combination of Lys and ultrasound > Arg approximate to Lys approximate to control, the combined treatments were effective than the individual treatments in increasing the zeta-potential, surface hydrophobicities, and solubility of myosin as well as the percentage of adsorbed myosin, but decreasing the hydrodynamic size of myosin, and inducing the transformations of myosin from a rigid structure to flexible ones. Therefore, the results suggested that ultrasound and L-lysine/L-arginine synergistically improved the physical stability of MSEs by inducing myosin to unfold and be negatively charged.