In vitro bioaccessibility and antioxidant activity of anthocyanins from mulberry (Morus atropurpurea Roxb.) following simulated gastro-intestinal digestion

In vitro simulated gastro-intestinal digestion of anthocyanins from mulberry (Morus atropurpurea Roxb.) was investigated in terms of bioaccessibility, antioxidant activity and the possible fate of anthocyanins in this study. Mulberry anthocyanins were isolated by aqueous two-phase system and purified by Sephadex LH-20 column separation, and Fraction 1 containing cyanidin-3-glycoside and cyanidin-3-rutinoside was obtained as the dominant fraction. The bioaccessibility of anthocyanins was greatly decreased after the intestinal digestion, the recoveries were only 0.34% (the IN sample) and 4.58% (the OUT sample), respectively. The radical scavenging ability showed that the digest have good antioxidant activity responsible for the phenolics generated from degradation of anthocyanins under intestinal environment. 18 phenolics were identified in the gastric–intestinal digest of Fraction 1 by HPLC–ESI-MS/MS, mainly small molecular flavonoids, phenolic acids and their derivatives. This study provided a scientific basis for further pharmacological activity of anthocyanins and their mechanisms of metabolic pathway research.

► In vitro simulated gastro-intestinal digestion of anthocyanins was studied. ► Bioaccessibility of anthocyanins after intestinal digestion was greatly decreased. ► Good antioxidant activity of the digest mainly attributed to the phenolics. ► 18 phenolics were identified in the gastric-intestinal digest of Fraction 1. ► Some phenolics might be inferred as the fate of anthocyanin decomposition.