| Summary: | 碩士 === 國立臺灣海洋大學 === 食品科學系 === 102 === Rabbitfish (Siganus fuscescens) is an economically valuable fish species in Penghu and northern Taiwan. The belly of this fish diffused a fermented odor, due to the digestion of algae. Because of the specific flavor, rabbitfish has been consumed worldwide. Rabbitfish is abundantly caught and usually produced by salting and subsequent sunlight drying. The purpose of this study was to understand the effect of seasonal (from Feb, 2013 to Dec, 2013) and regional (Keelung and Penghu) variation on the flavor, and the difference of flavor and fatty acids between commercial dried and fresh rabbitfish. In addition, acidic electrolyzed water (AEW) was used for preservation of the fresh rabbitfish, and the freshness changes was investigated at 4oC storage. The level of total-active components including inosine 5´-monophosphate (IMP), glutamic acid, glycine, alanine, serine, threonine, arginine, lysine and proline was higher in the muscle of rabbtfish collected from Sep. to Dec. in Keelung and Penghu, and lower from Feb. to Jun. in both places. Therefore, the better period for eating rabbitfish is caught from Sep. to Dec. in Keelung and Penghu. Commercial dried rabbitfish contained larger amounts of sweet/ umami amino acids (including glutamic acid, glycine, alanine, serine and threonine) and the level of total-active components than in fresh one. The results indicated that traditional processing methods could increase the contents of sweet/umami amino acids to enhance the flavor of fish. The fresh rabittfish was washed by AEW for 40 min and then stored at 4℃. At this condition, pH, trimethylamine (TMA), total volatile basic nitrogen (TVBN), aerobic plate count (APC) and K-value were lower than control group before day 6. It reveals that AEW treated group showed better preservation ability.
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