Physicochemical properties of muscle and natural actomyosin extracted from farmed Atlantic salmon (Salmo salar) stored at 4C

Properties of farmed Atlantic salmon (Salmo salar) obtained commercially were studied as a function of storage at 4C for 9 days. While pH increased gradually during storage for both samples, significant differences between samples were noted in water-binding capacity (WBC) of muscle, as well as surface hydrophobicity (S-o) and sulfhydryl contents of extracted natural actomyosin (NAM). Lower S(o)was observed for NAM extracted from muscle stored for 2 days, coinciding with high WBC of the muscle. In contrast, higher S-o from 5 to 7 day-stored samples coincided with minimum extractability and high apparent viscosity of NAM. Reactive sulfhydryl groups were higher at the beginning and end of storage. Generally, WBC of fish muscle was dependent on pH and related to changes in S-o of NAM, while apparent viscosity increased with S-o and disulfide content. The results indicate variability in functional properties of the salmon samples during cold storage, which could be attributed to changes in physicochemical properties of NAM.