益生菌发酵制备金针菇血管紧张素转化酶抑制肽

为了获得高活性的金针菇血管紧张素转化酶（ACE）抑制肽，该研究对益生菌发酵制备金针菇ACE抑制肽的工艺条件进行了优化，并采用超滤法对ACE抑制肽进行了分级分离和活性鉴定。试验以ACE抑制率为评价指标，对枯草芽孢杆菌（Bacillus subtilis）、酿酒酵母（Saccharomyces cerevisiae）和黑曲霉（Aspergillus niger）三种益生菌进行了筛选，优选出沉淀分离活性肽的最适pH，然后采用单因素和响应面设计对发酵条件进行了考察。结果表明，确定枯草芽孢杆菌为最适菌种；沉淀ACE抑制肽的最适pH为6；最佳发酵条件为蒸馏水与金针菇粉液料比5∶1（mL∶g）、发酵时间16 h、发酵温度37 ℃、金针菇粉用量35 g/500 mL三角瓶，于此条件下ACE抑制率实测值为（51.25±1.02）%；截留分子质量＜3 kDa的ACE抑制肽活性最强。

Preparation of Flammulina velutipes angiotensin converting enzyme inhibitory peptides by probiotics fermentation

In order to obtain highly active Flammulina velutipes angiotensin converting enzyme (ACE) inhibitory peptides, the conditions for preparing F. velutipes ACE inhibitory peptides by fermentation of probiotics were optimized, and the ACE inhibitory peptides were separated by ultrafiltration and the activity was identified. Using the ACE inhibition rate as an indicator, three probiotics (Bacillus subtilis, Saccharomyces cerevisiae and Aspergillus niger) were screened, and the precipitation method was selected to isolate the active peptides and the optimum pH was determined. Then the fermentation conditions were investigated by single factor and response surface design. The results showed that the Bacillus subtilis was determined as the optimum strain; the optimum pH for precipitating ACE inhibitory peptides addition was 6; the optimum fermentation conditions were liquid-solid ratio 5∶1 (ml∶g), fermentation time 16 h, temperature 37 ℃, and F. velutipes powder addition 35 g/500 ml triangular flask. The measured value of ACE inhibition rate was (51.25±1.02)% under the condition. The ACE inhibitory peptide with molecular mass cut-off less than 3 kDa had the strongest activity.