Effect of ice storage on the functional properties of proteins from shark (Scoliodon laticaudus) meat

Ice storage characteristics of Scoliodon laticaudus with reference to physicochemical and functional properties have been assessed. Total nitrogen content reduced to a value of 3.90 g/100 g from an initial value of 4.27 g/100 g of meat. Moisture content did not show much variation. The initial nonprotein nitrogen content which was 1.09% w/w of meat reduced to 0.98% during ice storage. Urea content of shark meat reduced by 25% during 12 days of ice storage. The increase in total volatile base nitrogen of shark meat was more than twofold at the end of 12 days of ice storage. Solubility of proteins showed an initial increase reaching a value of 87.9%, further reduced with ice storage. Gel filtration profile and SDS-PAGE pattern indicated aggregation of protein fractions and also showed dissociation or cleavage to small molecular weight fractions. Slope of reduced viscosity curve as a function of protein concentration decreased with ice storage period. Emulsion capacity of proteins from shark meat reduced from a value of 0.18 mL oil/mg protein to 0.14 mL oil/mg protein after 12 days of ice storage. Gel forming ability of shark meat monitored by dynamic viscoelastic measurement, gel strength, expressible water content and folding test showed that shark meat has got excellent ability to form gel and this property was marginally reduced during ice storage.