King Faisal University
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Item Restricted Changes in postmortem shelf-life indices of fish aquacultured in saudi arabia and stored in ice(Saudi Digital Library, 2001) Al-Najada, Ahmed Rashed; ELGASIM, A. ELGASIMChanges in the shelf life indices of iced aquacultured fish species (tilapia hybrid (Oreochromis niloticus x Oreochromis aureus) and the Common Carp (Cyprinus Carpio)} in Saudi Arabia and marine fish species from the Arabian Gulf {Shaeri (Lethrinus miniatus) and Hamour (Epinephelus chlorostigma). Physical, chemical, microbiological and sensory evaluations were performed at 0, 3, 5, 7, 10 and 13 days postmortem. Initially marine fish had slightly higher water activity (a.) than aquacultured fish. Generally none of the fish species had a below 0.9. Throughout the storage p period marine fish species had higher (P < .05) Hunter L* and b* and less a* values than aquacultured fish species. Expectedly, initial trimethylamine (TMA) values were higher (P < .05) in marine than in aquacultured fish species. TMA values increased with storage period, yet none of the species under investigation reached the rejection (30 mg TMA-N/100g) level. Initially aquacultured fish had higher (P <.05) total volatile basic nitrogen (TVBN) values than marine fish but none of the aquacultured fish species reached the rejection level (30 mg/100g) at any time of the storage period. Definitely marine fish species reached that limit by day 4 of storage. Initially and throughout the storage period tested, aquacultured fish had higher free fatty acids% (FFA) than marine fish species. Only TM and Carp reached the rejection limit of FFA (1.5%) by day 9 of storage All fish species under investigation had thiobarbituric acid reactive substances (TBARS) values of >0.6 mg MA/kg fish i.e they reached the rejection limit before the 7th day of storage. Relatively Tilapia female followed by Shaeri had the best lipid stability among all the species tested. None of the aquacultured fish species reached the maximum microbiological (TPC) limit (log 7.0 CFU/g) set by the ICMSF for fresh fish. However Hamour exceeded that limit by the 7th day of storage. Regardless of the fish type all microbial counts increased with the increase in storage period. Sensoryly the keeping time of the different fish species were found to be around 6.33, 9.44, 10.66, 10.9 and 11.0 days for Hamour, Carp, TF, Shaeri and TM, respectively.3 0