Antimutagenic activity and mechanism of black soybean koji

• Main Authors: Yu-Hsiang Hung, 洪裕翔
• Other Authors: 周正俊
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/24026889105378838185

碩士 === 國立臺灣大學 === 食品科技研究所 === 94 === In the present study, black soybean kojis were first prepared with Aspergillus awamori、Aspergillus oryzae BCRC30222、Aspergillus sojae BCRC30103、Rhizopus azygosporus BCRC 31158 and Rhizopus sp. No. 2, which are commonly employed as starter organism for production of oriental fermented foods. Changes of tatol phenolic and total anthocyanin contents as well as antimutagenic activity against 4- nitroquinoline- N- oxide (4-NQO) and Benzo[a]pyrene (B[a]P) of black soybean due to fermentation were examined. Besides, effect of cultivation temperature and fermentation period on the tatol phenolic, total anthocyanin content and antimutagenic activity of the A. awamori-prepared black soybean koji were also examined. Additionally, the mechanism of antimutagenic activity of the A. awamori-prepared black soybean koji was also investigated. The result showed tatol phenolic and total anthocyanin contents of black soybean were increased after fermentation. The methanolic extracts of black soybean kojis, regardless of starters used, exhibited a higher antimutagenic activity than that the non-fermented black soybean. While antimutagenicity of black soybean koji varied with the starter used. Among the various kojis examined, koji prepared with A. awamori showed the highest antimutagenic effect against 4-NQO and B[a]P. It also showed the highest tatol phenolic and total anthocyanin contents. In further studies, black soybean koji was prepared with A. awamori at different temperatures (25℃, 30℃ and 35℃) and various fermentation periods (1-5 days). It was found that the methanolic extract of A. awamori koji prepared at 30℃ for 3 days exhibited the highest antimutagenic activity and the highest total contents of phenolic and anthocyanin. Study on the possible antimutagenic mechanism, revealed that the bio-antimutagenic, desmutagenic and blocking effect all contributed to the antimutagenicity of A. awamori-koji against 4-NQO and B[a]P.