微生物固态发酵对绿豆酚类物质含量及抗氧化活性的影响

Effects of microbial solid-state fermentation on phenolic content and antioxidant activity of Vigna radiata

中文关键词:  绿豆  多酚  黑曲霉  抗氧化  固态发酵

英文关键词:Vigna radiata  polyphenol  Aspergillus niger  antioxidant  solid fermentation

中文摘要:

      目的 为提高绿豆酚类物质的生物可及性与抗氧化活性, 筛选适宜发酵菌种, 得到最优发酵参数。方法 采用植物乳杆菌(Lactobacillus acidophilus)、嗜酸乳杆菌(Lactobacillus plantarum)、酿酒酵母菌(Saccharomyces cerevisiae)、产朊假丝酵母(Candida utilis)、黑曲霉(Aspergillus niger)、米根霉(Rhizopus oryzae)对绿豆进行固态发酵, 通过测定发酵后绿豆游离多酚含量及多酚提取液的1,1-二苯基-2-三硝基苯肼自由基(1,1-diphenyl-2-picrylhydrazyl radical, DPPH·)清除率, 筛选出最优发酵菌种, 并对该菌种发酵工艺进行优化, 分析发酵对绿豆多酚、黄酮含量及抗氧化活性的影响。结果 黑曲霉为最优发酵菌种, 最优发酵条件为: 发酵时间10 d、发酵温度26.5 ℃、接菌量8 mL/100 g; 在此条件下绿豆游离酚、游离黄酮含量分别为17.56 mg/g、8.01 mg/g，均为未发酵绿豆的3~4倍; 游离酚、结合酚提取液的DPPH·清除率分别为91.93%、18.96%, 2,2’-联氮-双-3-乙基苯并噻唑啉-6-磺酸二铵盐阳离子自由基[2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) ammonium salt cationic radical, ABTS+·]清除率分别为77.86%、16.47%, 铁离子还原力分别为16.96 mmol/L、1.62 mmol/L。结论 黑曲霉固态发酵可显著促进绿豆酚类物质的释放或合成(P<0.05), 提高绿豆酚类物质的生物利用度与抗氧化能力, 以期为绿豆营养价值的提升及功能性食品的开发提供理论依据和技术支持。

英文摘要:

      Objective To improve the bioaccessibility and antioxidant activity of Vigna radiata phenols, screen appropriate fermentation strains, and obtain the optimal fermentation parameters. Methods This study used Lactobacillus plantarum, Lactobacillus acidophilus, Saccharomyces cerevicae, Candida utilis, Aspergillus niger and Rhizopus oryzae separately for solid-state fermentation of Vigna radiata. By measuring free polyphenol content and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·) clearance of polyphenol extract in fermented Vigna radiata, screened the optimal fermentation strain, optimized fermentation process for this strain, analyzed influence of fermentation on polyphenols, flavonoids content and antioxidant activity of Vigna radiata. Results Aspergillus niger was the optimal fermentation strain, the optimal fermentation conditions were: Fermentation time 10 d, fermentation temperature 26.5 ℃, inoculation amount 8 mL/100 g. Under these conditions, content of free phenols and free flavonoids was 17.56 mg/g and 8.01 mg/g, respectively, both of them were 3–4 times of unfermented Vigna radiata. The DPPH· clearance rates of free phenol and bound phenol extract were 91.93% and 18.96%, the 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) ammonium salt cationic radical (ABTS·+) clearance rates were 77.86% and 16.47%, the iron ion reducing power were 16.96 mmol/L and 1.62 mmol/L, respectively. Conclusion Aspergillus niger fermentation can significantly promote the release or synthesis of Vigna radiata phenols, improve the bioavailability and antioxidant capacity of Vigna radiata phenols, provide theoretical basis and technical support for the improvement of Vigna radiata nutritional value and the development of functional food.