The recovery, catabolism and potential bioactivity of polyphenols from carrot subjected to in vitro simulated digestion and colonic fermentation

Carrot powder digestion was researched utilizing an in vitro standardized static model associated with an in vitro colonic fermentation method to analyze the recovery, catabolism, and potential bioactivity of polyphenols from carrot. Twenty-seven polyphenols and their metabolites (hydroxybenzoic acids, hydroxycinnamic acids and its derivatives, etc.) were identified in samples before and after digestion/colonic fermentation, and the possible colonic pathways for major polyphenols were proposed. Polyphenols had low recovery during different phases of in vitro digestion (oral: −51.4%; gastric: −38%; intestinal: −35.3%, respectively). However, the concentration of polyphenols (p-hydroxybenzoic acid, gallic acid and protocatechuic acid) increased significantly after colonic fermentation for 12 h with 1391.7% recovery, then significantly declined after 48 h. Meanwhile, the released and catabolized polyphenols showed antioxidant activity and α-glucosidase inhibitory capacity (IC50 = 9.91 μg GAE/mL). The microbe community structure was regulated by fecal fermented carrot powder through improving relative abundance (RA) of beneficial microbiota and suppressed RA of various harmful bacteria. This work indicated that polyphenols from carrot potentially play a role in gastrointestinal and colonic health.