COMPARATIVE EFFECTS OF FROZEN STORAGE ON BIOCHEMICAL-CHANGES IN PINK PERCH (NEMIPTERUS-JAPONICUS) AND OIL SARDINE (SARDINELLA-LONGICEPS)

Effects of frozen storage on biochemical changes in pink perch (Nemipt erus japonicus) and oil sardine (Sardinella longiceps) were investigat ed. Significant (P<0.05) increases in peroxide value (PV), thiobarbitu ric acid (TBA) number and free fatty acids (FFA) were observed in pink perch and sardine during storage. While sardine showed a greater rate of lipid oxidation, hydrolysis of lipids to FFA was more pronounced i n pink perch. Total volatile-base nitrogen (TVBN) and trimethylamine n itrogen (TMAN) increased in both fishes during storage. While non-prot ein nitrogen (NPN) declined, alpha-amino nitrogen (AAN) showed an asce nding trend during storage. Salt-soluble proteins (SSP) reduced signif icantly (P<0.05), with the extent of reduction being more in sardine. SSP, in both species. showed significant negative correlations with PV , TEA and FFA. In pink perch, influence of lipid oxidation products on protein extractability was comparatively more than that of FFA. In sa rdine, lipid oxidised and hydrolysed products had an equally adverse i mpact on protein solubility.