Valorizing Pearl Mussel (Hyriopsis cumingii) into Hydrolysates: Impact of Different Ultrasonic Pretreatments and Proteases on Its Physicochemical and Functional Properties

Pearl mussel (Hyriopsis cumingii) meat is an underutilized byproduct. In this study, the effects of ultrasonic pretreatment (0–600 W) and protease type (flavorzyme, alcalase, bromelain, and trypsin) on the physicochemical, bioactivity, and functional properties of pearl mussel hydrolysates were systematically investigated. The results demonstrated that ultrasonic pretreatment increased the degree of hydrolysis (DH), with alcalase hydrolysates exhibiting the highest DH value (37.94%). Glutamic acid, aspartic acid, and leucine were identified as the predominant components. Specifically, at 300 W, the alcalase hydrolysate (UAH-3) exhibited excellent antioxidant activity. In contrast, at 600 W, the flavorzyme hydrolysate (UFH-6) and bromelain hydrolysate (UBH-6) demonstrated the highest α-glucosidase inhibitory and emulsion activity. Overall, these findings indicate that the combination of ultrasonication and enzymatic hydrolysis is a promising strategy for enhancing the utilization of pearl mussel byproducts and provides a solid theoretical basis for their application in functional foods and nutraceuticals.