Bioaccessibility of bioactive compounds and associated compounds to the indigestible fraction after in vitro digestion of three dry Capsicum annuum varieties

Abstract

Mexico has a wide variety of dry chilies used in Mexican food preparation because they are spicy, a property related to the bioactive compound named capsaicin. Apart from capsaicin, dry chilies have compounds such as phenolic compounds and tocopherols. Except for phenolic compounds, capsaicin and tocopherol have not been totally assessed to measure their release from the food matrix (bioaccessibility) after in vitro digestion. Therefore, this study is aimed at analyzing the bioaccessibility of phenolic compounds, tocopherols and capsaicinoids after in vitro digestion process of three dry chilies, namely, chiltepin, Colorado, and de Arbol, as well as the bioactive compounds associated with the indigestible fraction (IF). Results indicated that the bioaccessibility values of capsaicinoids were above 80% for all the three chili varieties without showing significant differences. Although these chilies showed high capsaicinoid bioaccessibility values, there were still compounds associated with the IF that could reach the colon and exhibit bioactivity. Regarding phenolic compounds, no differences in the bioaccessibility values were observed; however, there was a major concentration of flavonoids in the IF of the Colorado and de Arbol chilies, which could have a regulatory effect on the colonic microbiome. Regarding the bioaccessibility of α-tocopherol, there was a significant difference between de Arbol and the other two varieties (above 60%). The IF of Colorado chili was a source of α-tocopherol in the colon because it had the lowest bioaccessibility percentage. The overall results demonstrate that dry chilies are a source of bioactive compounds with bioaccessibility values favorable to human health.