混菌发酵苹果浊汁的益生菌筛选及其发酵动力学模型构建

Screening of Probiotics for Mixed Culture Fermentation of Cloudy Apple Juice and Construction of Kinetic Models

为筛选得到苹果浊汁发酵的较佳复合益生菌,以苹果浊汁为原料,从10 种常见益生菌菌株中筛选出具有耐酸、耐胆盐特性及良好发酵性能的优良菌株,并进行复合菌株间拮抗实验以及复合菌株较佳比例的研究。此外,根据筛选得到的复合菌株较佳比例发酵苹果浊汁,构建菌体生长、产物生成及底物消耗动力学模型,研究确定模型的动力学参数,并进行验证。结果表明:发酵苹果浊汁的较佳复合菌株组合为嗜酸乳杆菌6005、植物乳杆菌21805、发酵乳杆菌21828,根据感官评定及活菌数得到3 株菌株复合比例为1 1 1时,发酵苹果浊汁口感风味最佳,活菌数最高;建立复合菌株发酵苹果浊汁的菌体生长、产物生成和底物消耗动力学模型,模型理论值与实验值误差均小于10%,拟合较好,建立的动力学模型能够较好地预测复合益生菌发酵苹果浊汁发酵过程变化。

In order to select a suitable mixed culture of probiotics for cloudy apple juice fermentation, 10 strains of common probiotics were screened based on their acid and bile tolerance and fermentation performance. The antagonism between the selected strains was evaluated and the mixing ratio of these strains was determined. Furthermore, we modelled the kinetics of biomass growth, metabolite production and substrate consumption. The kinetic parameters of the models developed were determined and verified. The results showed that: 1) a mixture of Lactobacillus acidophilus 6005, Lactobacillus plantarum 21805, and Lactobacillus fermentum 21828 was found to be the most suitable for the fermentation of apple juice at a ratio of 1:1:1 as determined based on sensory evaluation and viable cell counts, and the fermented apple juice had the best flavor and mouthfeel as well as the highest viable cell counts;and 2) the errors between the theoretical values from all these kinetic models and the experimental data were less than 10%, suggesting excellent goodness of fit. Hence, the kinetic models could predict the dynamic changes during the mixed culture fermentation of cloudy apple juice.