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Title:	Effect of Libyan marinade and vacuum packaging on quality parameters of tilapia (oreochromus niloticus) and yellowstripe scad (Selaroides leptolepis) fillets during storage
Authors:	Fathia G. Moh. Shakhtour (P52527)
Supervisor:	Norrakiah Abdullah Sani, Dr.
Keywords:	Food -- Packaging Frozen foods -- Packaging Food -- Safety measures Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia
Issue Date:	1-Jan-2019
Description:	Improving food quality for consumers is of eminent importance; especially among fish meat being more obvious due to its quick spoilage. Therefore, in order to maintain and improve the quality of fish, a study on the efficacy of Libyan marinade (cumin, garlic and lime juice) single and in combination as natural preservatives with vacuum packaging (VP) on lipid components and fatty acid profiles during 35 days of ice and 6 months of frozen storage were investigated. Also the efficacy of Libyan marinade was monitored by microbiological, chemical and sensory quality changes throughout the 35 days of ice storage in tilapia (Oreochromus niloticus) and yellowstripe scad (Selaroides leptolepis) fillets. The result of the study indicated that the proportions of n-3 PUFA of marine fish (yellowstripe scad fillets) were higher than those of freshwater fish (tilapia fillets). Both fish fillets had higher DHA content than EPA, and the content was higher in yellowstripe scad than tilapia fillets. Highly significant differences (p<0.05) among and within fatty acid classes (SFA, MUFA, PUFA, n-3 PUFA, n-6 PUFA, UFA) were observed in fish types, treatments, and storage period. The highest antioxidant activity was in both tilapia and yellowstripe scad fillets treated with the mixture of lime juice, garlic and cumin which showed high accumulative inhibition of lipid peroxidation or reduction in values of PV, TBA and FFA due to a synergistic property of antioxidant activities in their marinade mixture when compared with the individual marination during the ice and frozen storage. Combination of cumin, lime juice and garlic together with VP were the most efficient inhibitor to reduce TVB-N and TMA-N values in tilapia and yellowstripe scad fillets compared to the other treatments. Significant differences (p<0.05) in chemical and sensory attributes were observed between VP treated and untreated fillets, as well as between different treatments during storage period. The VP treated fillets with the mixture of lime juice, garlic and cumin was the most effective in terms of shelf-life extension, as it gave the lowest total viable count (TVC), Pseudomonas spp. and H2S-producing bacterial counts, with values of log10 CFU g-1 at 7.51 ± 0.03, 7.09 ± 0.03, 6.82 ± 0.02, 6.17 ± 0.05, 7.18 ± 0.05 and 6.44 ± 0.03 for yellowstripe scad and tilapia fillets respectively, compared to individual treatments. The sensory scores for both tilapia and yellowstripe scad fillets with combine mixture of Libyan marinade were acceptable as indicated by the overall sensory acceptance. The combination treatment of tilapia and yellowstripe scad fillets maintained better quality (35 days), compared with untreated tilapia (30 days) and yellowstripe scad fillets (25 days) during ice storage. The isolated H2S-producing bacteria at the spoilage stage have been identified as, Shewanella putrefaciens. Salmonella spp. was absent in all VP treated and untreated tilapia and yellowstripe scad fillets during ice storage. This study concluded that the ready to cook tilapia and yellowstripe scad fillets treated with Libyan marinade had high quality. These findings suggest that the combination of lime juice, garlic and cumin mixture with the VP is recommended as a natural low-cost preservative for fish fillets for quality improvement through the delay of changes in the fatty acid profiles, retarding lipid oxidation indexes, TVB-N, TMA-N, TVC, H2Sproducing bacteria, Pseudomonas spp. and increasing the shelf-life during ice storage at 1 ± 1°C.,Ph.D.
Pages:	399
Call Number:	TP374.S533 2019 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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