Ultrasound-assisted freezing retards the deterioration of functional properties of myofibrillar protein in chicken breast during long-term frozen storage

Ultrasound-assisted freezing (UF) is a novel and fast freezing technology that has attracted much attention in the food processing industry in recent years. The objective of this study was to investigate the influence of UF, immersion freezing (IF), and air freezing (AF) on the functional properties (solubility, emulsification, and gelation) of myofibrillar protein (MP) in chicken breast during frozen storage (0–180 days). Compared to AF and IF samples, UF samples showed higher solubility, absolute potential, and emulsifying activity index, and lower turbidity and particle size during frozen storage (P < 0.05). Furthermore, UF treatment could better delay the deterioration of gel structure during storage. The gel water holding capacity and gel strength of MP in UF samples were higher than those in IF and AF samples during frozen storage (P < 0.05). The results of a hierarchical cluster analysis revealed that MP in the UF, IF, and AF samples had similar functional properties at 180, 90, and 60 days, respectively. Overall, UF retarded the decrease in functional properties of MP usually seen during frozen storage.