Regular and decaffeinated espresso coffee capsules: Unravelling the bioaccessibility of phenolic compounds and their antioxidant properties in milk model system upon in vitro digestion

Coffee is the most consumed beverage in the US and several other countries such as Brazil and Colombia. Coffee has been recognized for a myriad of health benefits including those arising from its antioxidant properties. However, to the best of our knowledge, there is no literature addressing the fate of phenolic compounds from espresso capsules considering the role of caffeine as well as the interaction with milk upon in vitro digestion. In this study, regardless of the sample (regular or decaffeinated espresso coffee capsule), oral and gastric digested samples showed lower contents of caffeine and phenolic acids than their undigested counterparts. In contrast, with recovery of up to 48%, only caffeic acid was present in the intestinal phase. Regular coffee samples showed a prooxidative action during the intestinal phase. In contrast, decaffeinated coffee prevented milk lipid peroxidation during the gastric and intestinal phases. A significant positive correlation existed between the caffeine concentration and the milk lipid peroxidation during the gastrointestinal phase. Thus, under the experimental conditions employed, decaffeinated coffee from commercial espresso capsules was considered the best choice in terms of prevention of the potential exposure of the gastrointestinal tract to products of milk lipid peroxidation.