Quality Assessment of Aquacultured Freshwater Fish Species during Storage in Ice

The following two freshwater fish species {Hybrid Tilapia (Oreochromisniloticus x Oreochromisaureus) and the Common Carp (CyprinusCarpio) were assessed for quality changes during13 days postmortem, stored in ice. Physical, chemical and sensory evaluations were performed at 0, 3, 5, 7, 10 and 13 days postmortem. None of the freshwater fish species had water activity (aw) below 0.9 throughout the storage period. Torry meter scores of freshwater fish species were (11.33). Among freshwater species common Carp had the highest value compared to Tilapia. However on day 3, Tilapia and Carp had similar L* values, but on day 5 and 7 Tilapia had higher L* values than Carp. For the b* values, Tilapia had slightly higher b* values than Carp (P greater than.05) through days 3, 5 and 7 of storage and the two species had similar redness values (a*) and carp had a* values higher than Tilapia. Saturation Index and Hue angle can improve our understanding to the changes in the color of the different fish species throughout the storage period. Within freshwater fish species, initially Tilapia and Carp had almost similar SI and Hue angles. On day 3 the two species had similar (P greater than 0.05) SI and Tilapia had Hue angles higher than Carp (P less than 0.05). On the 5th day of storage carp had the highest (P less than 0.05) SI. Generally, SI and Hue angle values of freshwater fish species flucuated over the storage periods. TMA values increased with storage period, yet none of the species under investigation reached the rejection (30 mg TMA-N/100g) level. Sensoryly the keeping time of the different fish species were found to be around 9.44and 11.0 days for Carp, and Tilapia, respectively.