| Summary: | 碩士 === 元培醫事科技大學 === 食品科學系碩士班 === 104 === It was reported that there were many antioxidant components in distillers' grains, therefore they could not be used only in food and feed, but also in cosmetics. In order to compare the activities of various kojis before and after fermentation and distillation, in this study, three kinds of koji, Aspergillus kawachii (white koji), Aspergillus awamori (black koji) and Aspergillus oryzae (yellow koji) provided by Biogenkoji Reseach Institute in Kagoshima Prefecture, Japan, were used for comparison. The comparison included determination of total phenolics content, DPPH radical-scavenging ability, superoxide (O2-．)-scavenging activity, reducing ability and tyrosinase inhibition ability. The result of total phenolics content and activity test showed that seed malt of kojis extracted with three kinds of solvents (water, methanol and ethanol) had the highest content and activity in all tests. Duringthe brewing process, the following koji rice samples collected：(1) samples after the first and third days(2)supernatants and precipitates after the second and fourteen days of fermentation. The results showed that A. awamori had the highest content in phenolics content and superoxide (O2-．)-scavenging activity, A. oryzae had the best performance in DPPH radical-scavenging and reducing ability, and A.kawachii had the best performance in tyrosinase inhibition during the koji preparation process. The comparison of the activity test with supernatants and precipitates from three kinds of koji after the seventh and fourteenth days of fermentation. The result showed that supernatants had higher activity after fourteenth days of fermentation and were better than precipitates. With regard to the result of comparison with the performance of supernatants form three kinds of koji after fourteenth days of fermentation, it showed A. oryzae had the highest content and best performance in phenolics content and DPPH radical-scavenging ability, A. awamori had the best performance in radical-scavenging and superoxide (O2-．)-scavenging and A.kawachii had the best performance in tyrosinase inhibition, A.kawachii had the best performance in tyrosinase inhibition. The supernatants residues after distillation had higher activity ability than precipitates. The supernatants residues of A. awamori had the highest content in phenolics content and reducing ability, A. oryzae had the best performance in DPPH radical-scavenging and superoxide (O2-．)-scavenging activity and A.kawachii had the best performance in tyrosinase inhibition, respectively. In this study, we found the three kinds of koji can be utilized, either before and after fermentation and distillation. Kojis and their fermentation broth or distillers' grains could be recycled and used for skin care products or feed to increase the utilization and reduce environmental pollution.
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