Effect of lactic acid fermentation and in vitro digestion on the bioactive compounds in Chinese wolfberry (Lycium barbarum) pulp

Two commercial probiotics, Lactobacillus helveticus 76 (Lh) and Bifidobacterium lactis 80 (Bla), were employed to investigate the effect of lactic acid fermentation and in vitro digestion on bioactive compounds in Chinese wolfberry pulp. The changes of antioxidant capacity of pulp were also studied. Our results demonstrated that Chinese wolfberry pulp was a suitable carrier for both probiotics. Lactic acid fermentation increased total phenolic, total flavonoids and betaine, and improved bioaccessibility of flavonoids and carotenoids in vitro digestion. Fermentation had no remarkable influence on the content and basic structure of polysaccharides, but reduced their particle size. In addition, fermentation improved the antioxidant activities of Chinese wolfberry pulp before and after in vitro digestion mainly due to the metabolism of polyphenols. This study thus would provide valuable information about the development of Chinese wolfberry as a functional drink fermented with probiotics.