(29b) Preparation of Low-Sugar Jujube Powder through Facultative Anaerobic Fermentation Process As Prebiotcics

Jujube, a traditional Chinese medicine and food, is rich in a variety of bioactive ingredients including carbohydrates, amino acids, vitamins and other nutrients. However, the large amount of reducing sugar in jujube may induce some adverse effects such as gastrointestinal discomfort. Here we prepared low-sugar jujube powder through facultative anaerobic fermentation and applied it to regulating the intestinal flora. First, jujube powder (JP) of 1-10 µm was prepared by cryogenic grinding. Saccharomyces cerevisiae was then applied to fermenting the jujube powder and the optimum fermentation conditions were conducted. Fermented jujube powder (FJP) was obtained after subsequent freeze-drying. The content of reducing sugar in FJP was reduced by 35% and it was observed that oligosaccharides with molecular weight (M_w) of 1000 Da were enriched during fermentation, which may be attributed to decomposition of polysaccharides. The types and contents of small molecule sugar were determined by ion chromatography (IC), showing that oligosaccharide in FJP was mainly composed of arabinose and galactose with the molar ratio of 2.80:1, while JP was mainly composed of monosaccharides, with the glucose-to-fructose molar ratio of 1.19:1. Furthermore, we examined the effect of FJP with an immunosuppression model induced by cyclophosphamide (CTX) on mice. It was found that the oral administration of FJP contributed to the increased diversity of gut microbiota and abundance of Lachnospiraceae, and improved the production of butyrate in the cecum content, which was considered to benefit the immunity system. These results showed the potential of the fermented low-sugar jujube powder as prebiotics to regulate the gut flora and enhance the immunity.