Effect of Fermentation by Lactiplantibacillus plantarum on Antioxidant and Nutritional Characteristics of Jujube Hot Water Extract

Abstract

The objective of this study was to evaluate the effect of fermentation by Lactiplantibacillus plantarum on the changes in antioxidant capacity and nutritional quality of jujube hot water extract. The dried jujubes were boiled at 100℃ for 3-4 h (the 1 st extract) and then another extract (the 2 nd extract) was prepared with the same manner after removing the 1st extract. Both extracts were inoculated with L. plantarum, followed by fermentation at 37℃ for 72 h. Change in the number of L. plantarum was measured during the fermentation, and the antioxidant capacity and nutritional quality of the both extracts and their corresponding fermented products were analyzed. The number of L. plantarum rapidly increased within 12 h, reaching the stationary phase, and was maintained until 72 h of fermentation. There was no significant difference in the sugar contents and total acidity among the 1 st , the 2 nd extracts and the fermented 1 st extract but the increased sugar content in the fermented 2 nd extract was observed. The fermentation by L. plantarum lowered the pH values, regardless of extracts. For nutritional components, no significant differences were observed between the 2 nd extract and its fermented products. The antioxidant capacity and total polyphenol content of the extracts was not significantly different from their corresponding fermented products. These results indicate that the fermentation by L. plantarum did not have a profound effect on antioxidant capacity and nutritional components of jujube hot water extract. Thus, a further study is needed to improve the nutritional and functional qualities of jujube hot water extract by fermenting it with other lactic acid bacteria.