Bioaccessibility of coffee bean hydroxycinnamic acids during in vitro digestion influenced by the degree of roasting and activity of intestinal probiotic bacteria, and their activity in Caco-2 and HT29 cells

Abstract

In coffee beans, especially roasted, a significant part of hydroxycinnamic acid (HCAs) and their esters chlorogenic acids (CHAs) is attached to melanoidins through both covalent and non-covalent bonds. Bound and, to a greater extent, unbound HCAs, including those released from the polymerized material during digestion, can be pivotal in preventing of many chronic civilization diseases. The aim of the study was to determine the amount of free CHAs and those released from coffee extracts during in vitro digestion in various sections of the gastrointestinal tract, in the presence and absence of probiotic bacteria. The concentration of free CHAs was the lowest in the stomach and achieved the highest levels in the large intestine. Probiotic bacteria caused significant release of CHAs, and in the colon their concentration was the highest. The studies with Caco-2 and HT-29 cell lines showed that digested coffee extracts had cytoprotective potential against tert-BOOH induced oxidative stress.