Effects of Ultrasonic Treatment on Solubility of Oyster Myofibrillar Protein

The objective of this study was to examine the impact of ultrasonic treatment on the solubility of oyster myofibrillar protein. Oyster myofibrillar protein was subjected to ultrasonic treatment at 200 W and 20–22 kHz for different durations (0, 10, 20, 30, 40 and 50 min) and evaluated for sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) patterns, endogenous fluorescence intensity, surface hydrophobicity, total sulfhydryl content, free sulfhydryl content, and disulfide bond content. SDS-PAGE results demonstrated a noticeable increase in the intensity of myosin heavy chain bands but no changes in the intensity of protein bands after ultrasonic treatment for a certain period. In addition, the intrinsic fluorescence intensity of myofibrillar protein decreased, which was accompanied by the exposure and conversion into disulfide bonds of hydrophobic groups buried inside myofibrillar protein. These changes significantly improved the solubility of oyster myofibrillar protein. Nevertheless, excessive ultrasonic treatment led to excessive modification of the protein, resulting in a decline in its functional properties. The findings of this study provide a theoretical foundation for the application of ultrasonic treatment to oyster myofibrillar protein and for expanding its potential applications in improving the solubility of food products.