The first tract of alimentary canal as an extractor. Release of phytochemicals from solid food matrices during simulated digestion

The release of some phytochemicals (polyphenols, flavonoids, anthocyanins, carotenoids) from peach, plums, prunes, walnuts and tomatoes using an in vitro model simulating oral-gastro-hepato-pancreatic digestion has been investigated. Most of phytochemicals are extracted during the oral phase, and the amount of bioaccessible polyphenols, flavonoids and anthocyanins increased during gastric digestion in all the analyzed fruits. The transition in the hepatopancreatic environment caused a decrease in total polyphenols, whereas flavonoids (except anthocyanins) were not degraded. In most of the tested fruits, the hepatopancreatic digestion did not affectthe extraction of polyphenols and flavonoids except in walnuts, for which this phase caused an important release of both of them. Our results suggest that the first tract of alimentary canal may act as an extractor of phytochemicals where the antioxidantcompounds are progressively released from food matrix and are made available for the absorption or to exert their biological effects in this area.