Safety evaluation of natto-red bean and its effects on the intestinal microflora

• Main Authors: Shin-yu Huang, 黃詩愉
• Other Authors: Yun-Chin Chung
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/12530913876991192532

碩士 === 靜宜大學 === 食品營養研究所 === 98 === Our previous study showed that the antioxidant capacity and total polyphenol content of 50% ethanol extract from red bean fermented by Bacillus subtilis were greater than that of from unfermented red beans. On the other hand, research showed that soybean fermented by B. subtilis could improve the intestinal functions. This study aimed to establish the optimum conditions for the B. subtilis-fermented red bean (called natto-red bean), and to evaluate the safety of natto-red bean and its effect on intestinal microflora using the Sprague-Dawely (SD) rats as a animal model. The α-diphenyl-βpricrylhydrazyl（DPPH）radicals scavenging effect and fibrinolytic activity were used as the index of fermentation result, and the Ames test, micronucleus test, 14-day feeding toxicity study (acute toxicity) and 28-day feeding toxicity study (subacute toxicity) were performed for safety evaluation. Intestinal microflora, such as Lactobacillus spp., Bifidobacteria spp., Escherichia coli, and Clostridium perfringens were determined as well. The results of this study showed that the optimum conditions for the production of Natto-red bean were to ferment Kaohsiung NO.5 red bean (Phaseolus radiatus L. var. aurea Prain) with addition of 1% Glucose using Bacillus subtilis at 30℃for 96 hr. The genotoxicity tests including in vitro and in vivo assays, Ames test and micronucleus test, respectively, showed the water extract of Natto-red bean had no genotoxicity. Animal feeding experiments, confirmed by 14-day feeding toxicity study and 28-day feeding toxicity study, showed that the natto-red bean had no toxicity, and the no-observed-adverse-effect level (NOAEL) was greater than 1 g / kg BW. The natto-red bean had no effect on intestinal microflora inculding Lactobacillus spp., Bifidobacteria spp., E. coli, and C. perfringens. In conclusion, the natto-red bean had no toxicity, and had no prebiotic effect either in rats.