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 ζ-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 ≈ a combination of Lys and ultrasound > Arg ≈ Lys ≈ control, the combined treatments were effective than the individual treatments in increasing the ζ-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.