| Summary: | 碩士 === 弘光科技大學 === 食品暨應用生物科技所 === 99 === The γ-aminobutyric acid(GABA) tea ethanolic extract was prepared according to the optimal extraction conditions of the previous study. The purposes of this study were designed to investigate the extraction yield, bioactive components, antimutagenicity, antimicrobial activity of GABA tea ethanol extract, and their application in pork patties. The results showed that the extraction yield, total polyphenol, gallocatechin, epigallocatechin, epicatechin, epigallocatechin gallate, gallocatechin gallate, epicatechin gallate, total catechins, GABA, theanine and caffeine contents are 32.21 0.91%, 492.35 2.87, 2.54 0.34, 40.03 2.43, 19.52 0.48, 82.97 2.92, 1.77 0.34, 18.49 0.37, 165.32 2.98, 5.79 0.32, 6.24 0.37, 68.01 1.32 mg/g extract, respectively. In the antimutagenicity, in the range of 0.25-5.0 mg/plate, neither toxicity and nor mutagenicity was observed in 50% etanolic extract of GABA tea leaves toward Salmonella typhimurium TA98 or TA100 with or without S9 mix. At 5 mg/plate, the inhibitions of mutagenicity of TA98 and TA100 strains induced by 4-nitrio-o-phenylenediamine and sodium azide were 44.2% and 35.3%, respectively. At 2.5 mg/plate, the inhibitions of mutagenicity of TA98 and TA100 strains induced by 2-aminoanthracene were 100% and 99.9%, respectively. In the antimicrobial activity, the antimicrobial activities increased when the amounts of tea extracts increased. Tea extracts has potential antimicrobial activities effect on G (+) Staphylcoccus aureus and Bacillus cereus than that of Salmonella typhimurium, E. coli and E. coli O157:H7. Furthermore, the antimicrobial activities of tea extract are higher than those of potassium sorbate. In pork patties, the CIE a* values of refrigerated-stored, CIE a* values and total plate counts (TPC) of froze-stored samples significantly decreased during storage, whereas the TPC of refrigerated-stored, TBARS values of refrigerated- and froze-stored showed a reverse trend. The pH value, CIE L* and b* values, and the sensory quality characteristics (including color, flavor, juiciness, texture and overall) of each cooked pork patties were not significantly different during storage. As for the effect of the addition amount of extract, the moisture content of refrigerated- and froze-stored samples were not significantly different. The pH value, CIE L* value and TPC of pork patties decreased with increasing tea extract level, whereas, the CIE a* and b* values of samples showed a reverse trend. In sensory evaluation, the hedonic scores of samples prepared with 4-5 g GABA ethanol extracts addition for 1 kg pork patties are higher than other tested samples.
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