Effects of in vitro digestion and in vitro colonic fermentation on stability and functional properties of yerba mate (Ilex paraguariensis A. St. Hil.) beverages.

Yerba mate (Ilex paraguariensis) is a plant that grows naturally in South America. From its leaves and thin stems different kinds of beverages are prepared (chimarrão, tererê and tea mate), all of them rich in bioactive substances. The aim of this study was to evaluate the influence of in vitro gastrointestinal digestion and colonic fermentation on the stability of the polyphenols and on the antioxidant, antimicrobial and antitumoral activities of the yerba mate beverages. The phenolic chromatographic profile revealed that both the in vitro digestion and the colonic fermentation caused a pronounced decrease in 3,5-O-dicaffeoylquinic acid and 5-O-caffeoylquinic acid in the preparations. However, 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid and salvianolic acid I were only barely affected in all preparations. Despite the decrease in the phytochemicals content, yerba mate beverages maintain their functional properties such as antioxidant, antibacterial and antitumoral activities.