Relationship Between Functional (Fat Binding, Emulsifying) and Physicochemical Properties of Muscle Proteins. Effects of Heating, Freezing, pH and Species

Properties of proteins in salt extracts from beef top round and rockfish fillet changed upon heating and were dependent on pH, freezing, species and sample variability. Generally, heating to >45°C, freezing or lower pH (5.5) decreased dispersibility, increased surface hydrophobicity and slightly decreased sulfhydryl content. Emulsifying and fat binding properties followed parallel trends, being improved under conditions favoring combinations of high dispersibility, hydrophobicity and sulfhydryl content (i.e., heating at <45°C, higher pH, unfrozen). However, high temperature‐low pH heating improved fat binding and favored gelation, which might be explained by hydrophobic interactions. Significant (P<0.001) multiple regression models were obtained describing relationships between physicochemical and functional properties of beef and fish proteins.