Bioaccesibility and Bioactivity of Betalains and Polyphenols from Opuntia Joconostle ( Cactaceae ) Fruits

Abstract Opuntia joconostle fruits, commonly known as xoconostle, are traditionally consumed in Mexico. The mesocarp constitutes the edible part of the fruit, whereas pericarp and endocarp are discarded even though they are rich in phytochemicals. This work evaluates, the bioaccessibility and in vitro bioactivity of betalains and polyphenols (free and bound) from these fruit fractions after simulated gastrointestinal digestion and colonic fermentation. Betaxanthins showed the highest gastrointestinal bioaccessibility (up to 53.5% in pericarp), and ferulic acid was the most bioaccessible phenolic compound. Colonic fermentation generated microbial catabolites, including 4-hydroxyphenylacetic acid (68.0 ± 3.1 μg) and 3-phenylpropionic acid (58.9 ± 0.3 μg), and increased acetate and propionate production as compared with the raffinose control. Digested fractions inhibited pancreatic lipase, dipeptidyl peptidase IV, α-amylase and α-glucosidase, and exhibited cellular antioxidant and antiproliferative activity. These findings demonstrate that xoconostle by-products retain bioaccessible phytochemicals and represent a source of fermentation-derived metabolites with antioxidant, enzyme-inhibitory, and potential prebiotic effects.