Quality changes in the muscles of Wallago attu during frozen storage (-122C) conditions

摘要

The present study was aimed to investigate the effect of frozen storage on the proximate, biochemical and microbial profile of the muscle of a silurid cat fish (Wallago attu). The fish muscle was subjected to the frozen storage for a period of one month and the analysis was carried out at an interval of 10 days. It was observed that proximate composition viz. protein, lipid, moisture and ash content decreased significantly (P0.05) with increase in the duration of frozen period. The fresh (unfrozen) samples revealed the highest values for all i.e.15.45-0.2% for protein, 4.02-0.04% for lipid, 81.66-0.03 for moisture and 1.48-0.1% for ash while the least values were observed at the end of one month frozen storage period i.e.10.14-0.015%, 2.36-0.03%, 74-0.05% and1.33-0.02% for protein, lipid, moisture and ash respectively. pH of fish ranged between 5.9 to 7.1 while the biochemical parameters viz.,Free Fatty Acids (FFA) and Thiobarbituric acid (TBA) showed an increasing trend with increase in frozen storage period. Similarly, the microbial count for Total Plate Count (TPC), Coliform Count (CC) and Psychrotrophic Count (PC) increased gradually from 2.18-0.02 log cfu/g, 2.02-0.04 log cfu/g and 2.43-0.03 log cfu/g on day 0 to 6.87-0.1 log cfu/g, 5.25-0.2 log cfu/g and 5.99-0.02 log cfu/g on day 30threspectively. Thus, considering the importance from consumer point of view, these studies reveal that a significant loss is observed in fish during frozen storage. However, it could be implied that fish could be kept under frozen conditions when preservation is of utmost importance, so as to retain its taste and nutrition.