Biochemical and sensory evaluation of hilsa fish (Hilsa ilisha) during frozen storage

Abstract

Quality in terms of biochemical and sensory evaluation of hilsa fish( Hilsa ilisha) during frozen storage at -20 degrees C was studied for a period of 75 days at an interval of 15 days. Biochemical study showed a slight decrease in protein and lipid content. Non protein nitrogen (NPN) content increased from 0.05% to 0.87%, total volatile base nitrogen (TVB-N) increased from 5.60 to 27.20 mg/100 g fish and the trimethylamine nitrogen (TMA-N) also increased from 1.68 to 10.0 mg/100 g. Peroxide value of the oil was 5.53 meq/kg oil at the beginning and this value went up to 16.2 meq/kg oil at the end of frozen storage. Free fatty acid value was 2 to 10% from the beginning and completion of frozen storage. These values indicate that the quality of the frozen stored hilsa fish is quite good and the fat oxidation of this species during frozen storage is very minimum, i.e. in initiation phase. The results of the whole study indicate that despite some changes in the biochemical and sensory properties during prolonged frozen storage at -20 degrees C the hilsa fish appeared to be suitable for frozen storage preservation.