植物乳杆菌58发酵豆乳产大豆异黄酮苷元条件的优化

本研究通过测定植物乳杆菌58在不同碳源中的生长和产β-葡萄糖苷酶情况,筛选菌株的最适碳源,并确定接种至豆乳的最佳时间.在接种量、糖含量、发酵时间和发酵温度等单因素实验基础上,根据Box-Behnken中心组合原理进行响应面实验设计,以大豆异黄酮苷元含量为指标,进一步优化菌株58发酵豆乳产大豆异黄酮苷元条件.结果显示,植...

Optimization of Soy Isoflavone Aglycone Production from Soybean Milk Fermented by Lactobacillus plantarum 58

In this work,the growth andβ-glucosidase production of Lactobacillus plantarum 58 in different carbon sources were analyzed to optimize carbon source of the strain,and then the best time for inoculation to soymilk was obtained.On the basis of single-factor experiments(such as inoculation amount,sugar content,fermentation time,and fermentation temperature),the response surface experiment was designed according to the Box-Behnken central combination principle.The soy isoflavone aglycone content was used as an indicator to further optimize the fermentation conditions of soybean milk by Lactobacillus plantarum 58.The results showed that the optimal carbon source for the growth andβ-glucosidase production of Lactobacillus plantarum 58 was lactose,and the enzyme activity reached 0.66 U/mL,which was significantly higher than that of fructose,sucrose,glucose and maltose(p<0.05).The strain cultured in a lactose carbon source for 18 h couldproduce the best enzyme activity(0.75 U/m L),and the growth was good.Results of response surface optimization experiments showed that the optimal conversion condition of soy isoflavones wasas follows:inoculum amount of 3.80%,sugar content of 5.80%,fermentation temperature of 38.10℃,fermentation time of 9.80 h.Under this condition,the predicted value of soy isoflavone aglycone content reached 68.63 mg/L,which was not significantly different from the experimental value 68.16 mg/L,indicating that the construction of the secondary model was scientific and accurate.Compared with the soy isoflavone aglycone content(59.64 mg/L)before optimization,it increased by 15.07%.The results of this work could be helpful to the conversion of soy isoflavone glycosides in lactic acid bacteria fermented soymilk to high bioactivity and availability of soy isoflavone aglycones.