In Vitro Intestinal Bioaccessibility and Colonic Biotransformation of Polyphenols from Mini Bell Peppers (Capsicum annuum L.).

To the best of our knowledge, "sweet mini bell" peppers have not been extensively investigated. In this study, we evaluated the bioaccessible phenolic compounds released during intestinal digestion and identified and quantified the microbial metabolites derived from phenolic compounds bioconversion during the in vitro colonic fermentation. A total of 66 phenolic compounds were determined. The results obtained in this study indicate that hydroxycinnamic acids (22 to 32 mg/100 g dw) and flavonoids (99 to 102 mg/100 g dw) headed by quercetin, luteolin and kaempferol glycosidic derivatives were the main bioaccessible phenolic compounds during in vitro intestinal digestion of mini bell peppers. The yellow variety contained the highest concentration of bioaccessible flavonoids (80 mg/100 g dw). For the first time in mini bell peppers, dihydroferulic acid was detected, in the three varieties studied. 3-(4-hydroxyphenyl)propionic acid was the major metabolite found after 12-24 h fermentation of all samples (44 to 102 µM/L). Further cell culture or in vivo studies are needed to elucidate the biological activities of the phenolic compounds identified in mini bell peppers.