Abstract:To investigate the effects of functional oligosaccharides on the fermentation characteristics and cold storage of milk fermented using Lactobacillus plantarum (L. plantarum) ZDY2013, the fermentation characteristics and pH variations of L. plantarum in the fermented milk were evaluated upon adding different prebiotic carbohydrates, namely xylo-oligosaccharides, isomaltose oligosaccharides, and their composites, into the fermented milk. At the same time, the water holding capacity and antioxidant activity of the fermented milk during cold storage were analyzed. The results revealed that L. plantarumcan be metabolized with different functional oligosaccharides at different concentrations. Compared with glucose, oligosaccharides added to the fermented milk were found to be more beneficial for the growth of L. plantarum. More specifically, at the composite concentration of 3.0%, the number of viable bacteria in the fermented milk increased significantly, while the pH of the fermented milk reduced. During 21 days of cold storage, the number of viable bacteria in each experimental group reduced, but it was higher than 108 cfu/g. Meanwhile, the pH was relatively stable after 7 days of cold storage, and the water holding capacity increased continually. All the experimental groups exhibited the strongest DPPH radical scavenging abilities on day 7, while the ABTS and hydroxyl radical scavenging abilities are declined. Additionally, at the same concentration, the addition of oligosaccharide composites outperformed that of glucose. The results of this study will provide a theoretical basis for the application of functional oligosaccharides and L. plantarum ZDY2013 in the development of dairy products.
