Changes in Structural and Functional Attributes of Fish Mince Proteins in Presence of Cosolvent During Frozen Storage

The effect of polyhydric alcohol, mannitol, on the properties of proteins from Sardinella longiceps has been investigated. Calcium ATPase activity of the proteins decreased during frozen storage. Ca²⁺ATPase activity of mannitol treated samples was higher up to 60 days of storage as compared to untreated samples. Emulsion capacity of proteins decreased as a function of storage. Thermal denaturation profile of proteins revealed no change in apparent thermal transition temperature (app.T_m) from a control value of 57.5°C, in presence of mannitol. Scanning electron micrographs showed an increase in porosity of muscle tissues in the presence of mannitol. These results indicate the stabilizing effect of mannitol at low temperature on the fish muscle protein by retaining structure and functional properties of the muscle during frozen storage.