基于梯度驯化法筛选适宜辣木发酵的酵母菌

Screening suitable yeasts for Moringa oleifera fermentation based on gradient acclimation method

通过对4株酵母菌(2株酿酒酵母、1株产朊假丝酵母、1株热带假丝酵母)进行驯化,使其适应辣木液环境,并以草酸、可溶性蛋白、蛋白降解率、总游离氨基酸、SDS-PAGE蛋白电泳条带的变化为指标筛选降解辣木抗营养因子最强的酵母发酵剂。结果表明,热带假丝酵母菌对辣木的降解效果均优于其他酵母菌,在辣木液中的活菌数≥4×106 CFU/mL,pH值为4.5~5.0,糖度值为1.8~2.2。发酵至第3天时,可溶性蛋白的产生量为64.41 mg/mL,氨基酸产量为398.732 mg/100g,蛋白电泳条带在20~70 kDa的几乎全部消失,且对草酸或草酸盐的降解率达70%以上。热带假丝酵母菌发酵能够显著提高辣木营养物质的利用率,并有效改善辣木的辣味和苦涩味,提升口感。

Four yeasts strains(two Saccharomyces cerevisiae strains,one Candida utilis strain,one Candida tropicalis strain)were domesticated to adapt to the environment of Moringa oleifera liquid.Oxalic acid,soluble protein,protein degradation rate,total changes of free amino acids and SDS-PAGE protein electrophoresis bands were used as indicators to screen the yeast starter that could degrade Moringa anti-nutritional factors.The results showed that the degradation effect of Candida tropicalis on Moringa was better than other yeasts,the number of viable cells in Moringa liquid was larger than 4×106 CFU/mL,the pH was 4.5-5.0,and the sugar content was 1.8-2.2.On the 3rd day of fermentation,the amount of soluble protein produced was 64.41 mg/mL,the amount of amino acid produced was 398.732 mg/100g,and the protein electrophoresis bands between 20 and 70 kDa almost all disappeared,and the degradation rate to oxalic acid or oxalic acid was over 70%.Candida tropicalis fermentation could significantly improve the utilization of nutrients in Moringa,and effectively improve the spicy and bitter taste of Moringa,and enhance the taste.