益生菌发酵苹果汁过程中总酚酸变化与动力学研究

为了使苹果汁中结合态多酚变为游离态多酚,提高苹果汁的功能性多酚单体含量,利用嗜酸乳杆菌6005、植物乳杆菌21805和发酵乳杆菌21828混菌发酵复合苹果汁,分析苹果汁发酵过程中活菌数及理化成分变化,建立混菌生长和总酚酸变化动力学模型,并进行模型验证。结果表明：混合益生菌在复合苹果汁中生长良好,活菌数达到2.68×108CFU/mL,发酵过程中总糖含量下降,可滴定酸含量上升,总酚酸含量总体呈上升趋势,绿原酸及没食子酸等功能性酚酸类多酚单体含量增加;建立了复合益生菌发酵苹果汁的菌体生长动力学模型和总酚酸增加量变化动力学模型,模型理论值与试验值的平均误差小于10%,说明建立的动力学模型能够较好地预测混合益生菌发酵苹果汁中总酚酸的变化过程。

Changes and Kinetics of Total Phenolic Acids of Apple Juice Fermented by Probiotics

In order to change the binding polyphenols into free polyphenols in apple juice, improve the content of functional polyphenols, and develop products of apple juice with health care function, Lactobacillus acidophilus 6005, Lactobacillus plants 21805 and Lactobacillus fermentum 21828 were mixed and fermented with apple juice, which was mixed with three varieties of Aksu, Qinguan and Granny Smith. The changes of viable cell numbers and physicochemical composition in apple juice fermentation process were studied. In addition, the kinetic model of bacterial growth and the kinetic model of total phenolic acid incremental change were established and verified. The results showed that probiotics grew well in apple juice, and the number of viable bacteria exceeded 2.68×108CFU/mL. During fermentation, the total sugar content was decreased, the titratable acid content was increased, and the total phenolic acid content was increased. Moreover, the content of several functional phenolic polyphenol was increased, such as chlorogenic acid and gallic acid. Probiotic fermentation changed the quality of apple juice. The kinetic model of bacterial growth and the kinetic model of total phenolic acid change were established. The average error between the theoretical and experimental values of the model was less than 10%. The fitting was good and the established kinetic model could predict the fermentation process. The research results provided a theoretical basis for the development of functional juice beverage products.