Phytochemical profiles, antioxidant, and antiproliferative activities of red-fleshed apple as affected by in vitro digestion.

The aim of this study was to characterize the phenolic profiles in the extracts and digesta (after in vitro digestion) of different red-fleshed apple fruit parts and to assess the effects of digestion on the in vitro antioxidant capacity and antiproliferative activity. The main polyphenols were identified by UPLC-MS/MS and HPLC. Our results indicate that the digesta had less total phenolics, flavonoids, and anthocyanins, but more free phenolic acids, than the extracts. An analysis of the in vitro antioxidant capacity (including ABTS radical scavenging activity, DPPH radical-scavenging capacity, ferric reducing antioxidant power [FRAP], and cellular antioxidant activity [CAA]) revealed that the digestion decreased the ABTS, DPPH, and FRAP values, but increased the CAA values, relative to the corresponding values for extracts. These results suggest that the digestion improved the effectiveness of the phenolic substances. Moreover, our findings imply that the digestion promoted the antiproliferative activity of red-fleshed apple peels and flesh relative to the extracts. Future in vivo investigations are warranted based on the results of the current study. PRACTICAL APPLICATION: The effects of an in vitro digestion on the phenolic compounds as well as the antioxidative and antiproliferative activities of red-fleshed apple were evaluated. The resulting data may clarify the bioavailability of the polyphenols in red-fleshed apple and enable scientists and consumers to exploit natural polyphenols.