Fate of polyphenols in black goji berry (Lycium ruthenicum Murr.) upon in vitro and in vivo digestion

The low stability of polyphenols during gastrointestinal digestion affects their biotransformation and bioavailability in the human body. That in turn affects the therapeutic potential of black goji berry. Thus, the present study was conducted to explore the impact of digestion on the fate of polyphenols present in black goji berries. Black goji berries exhibit high levels of phenolics which were reduced during gastrointestinal digestion. The crude extract of goji berry exhibited potent antioxidant activity as accessed by DPPH (151.34 mmol TE/g), ABTS (202.89 mmol TE/g) and FRAP assay (64.43 mmol TE/g), which were reduced after in vitro gastrointestinal digestion. However, the pronounced reduction was observed after in vivo intestinal digestion as determined by DPPH (23.23 mmol TE/g), ABTS (141.29 mmol TE/g) and FRAP assay (25.53 mmol TE/g). Furthermore, UPLC-Q-TOF-MS chromatograms revealed that the chemical structures of anthocyanins were stable during gastric digestion and significant alterations were observed during intestinal digestion.