fatty acids changes during frozen storage in several fish species from south caspian sea

changes in the fatty acid content, during frozen storage at -24°c of caspian kutum (rutilus frisii kutum), golden grey mullet (liza aurata), common carp (caprinus carpio), pike perch (sander lucioperca) and common kilka (clupeonella cultiventris caspia), caught from south caspian sea were studied in the present work. changes in saturated fatty acids (sfas), monounsaturated fatty acids (mufas), polyunsaturated fatty acids (pufas), ecosapentaenoic acid plus docosahexaenoic acid/palmitic acid (epa+dha/c16), n3 pufa/n6 pufa (n3/n6) and polyunsaturated fatty acids/saturated fatty acids (pufa/sfa) were investigated during a six month period. results indicated that due to the decrease in unsaturated fatty acids particularly pufas (9.25-23.03%), and lower ratios of n3/n6 (2.02-6.06), epa+dha/c16 (polyene index; 0.21-0.65) and pufa/sfa (0.18-0.64) the poststorage nutritional values of these species significantly decrease.