Role of ultrasonic freezing-treated pork dumpling filling during frozen storage: Insights from protein oxidation, aggregation, and functional properties.

• Ultrasonic freezing (UF) delayed MP functional deterioration. • UF improved the quality of dumpling during frozen storage compared to IF and AF. • UF samples exhibited greater solubility than IF and AF samples. • UF samples had superior protein thermal stability compared to IF and AF samples. The effects of air freezing (AF), immersion freezing (IF), and ultrasonic freezing (UF) on the oxidation, aggregation, and functional properties of myofibrillar protein (MP) in pork dumpling filling during frozen storage were investigated. The findings demonstrated that, compared to AF and IF treatments, UF treatment had higher total and reactive sulfhydryl content, solubility, and absolute zeta potential. Conversely, it exhibited lower values in carbonyl content, dityrosine content, turbidity, and particle size within the same storage time (p < 0.05). SDS-PAGE revealed that UF treatment delayed the oxidation and excessive aggregation of MP during frozen storage. Moreover, samples treated with UF at 180 days (d) displayed similar functional and qualitative characteristics to those treated with IF at 90 d or AF at 60 d, as per the hierarchical cluster analysis findings. In conclusion, UF effectively delayed the oxidation, aggregation, and loss of functional properties of MP in pork dumpling filling during frozen storage. [ABSTRACT FROM AUTHOR]