Evaluation of bioaccessibility and functional properties of kombucha beverages fortified with different medicinal plant extracts

Abstract

In this study, sweetened black and green tea were utilized as substrate for kombucha fermentation. Linden, lemon balm, sage, echinacea, mint, and cinnamon infusions were added to kombucha to design a novel beverage with Unproved functional and organoleptic characteristics. After fermentation, the antioxidant capacity (AC) of the kombucha increased by 13.96% 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), 48.90% ferric reducing antioxidant power (FRAP), and 55.54% cupric reducing AC (CUPRAC). On days 0 and 9 of storage, the bioaccessibility of the total phenolics and AC (FRAP and CUPRAC) in all of the samples showed a significant increase after gastric and intestinal digestion when compared to pregastric digestion (P < 0.05). The AC (DPPH) after in vitro digestion at the beginning and end of storage in all of the beverages also increased after gastric digestion when compared to pregastric digestion (P < 0.05); however, it decreased after intestinal digestion (P < 0.05). By conducting in vitro and in vivo studies, the effects of kombucha on health and nutrition need to be further investigated.