Physico-chemical and functional properties of proteins from pelagic fatty fish (Sardinella longiceps) as a function of water washing

The minced meat from oil sardine (Sardinella longiceps) was subjected to once, thrice, and five water washings. The changes in proximate composition of meat, physico-chemical and functional properties of proteins as affected by number of washings were investigated. A positive correlation (p<0.05) existed between number of washings and fat content, water absorption capacity, gel strength, expressible water content and emulsion capacity of meat. A reduction in low Molecular weight components of proteins during different washings was evident from gel filtration profile. The sodium dodecyl sulfate polyacrylamide gel electrophoresis patterns of total proteins revealed that increase in myosin heavy chain content and decrease in the concentration of 55 and 36 kD components with number of washings. The dynamic visco-elastic behavior of once washed sardine meat in the temperature range of 30-90 degrees C had higher ability to form elastic component (G') than thrice and five times washed meat.