Molecular mechanisms underlying tenderness in Pork: Insights from physicochemical and rheological properties

In this study, we aimed to explore the changes in physicochemical and rheological properties of pork with different tenderness levels during storage, and to analyze the correlation between such alternations. Using the longissimus dorsi with varying tenderness as the research subjects, we systematically analyzed key indicators such as physical and chemical indexes, stress relaxation, and microstructure during storage. Our results indicated that the shear force in pork meat decreased from 15.5 N to 11.8 N with an increasing storage time, indicating a significant improvement in tenderness. Meanwhile, physical and chemical indexes, such as moisture and protein contents, displayed a downward trend. Stress relaxation reduced over time and the secondary protein structures were altered, with muscle fiber structure becoming increasingly blurred. We performed Pearson’s correlation analysis, with further confirmed the significant correlation between tenderness and the physicochemical and rheological properties. The results of this study provide important theoretical support for revealing the molecular mechanisms underlying pork tenderness. • The changes in physicochemical and rheological properties of pork with different tenderness levels. • The loosening of muscle fibers lead to an improvement in pork tenderness. • The relationship between tenderness, physicochemical indicators, and rheological properties was analyzed by Pearson’s correlation.