Enhanced phenolic content and antioxidant activity of broad bean natto following simulated in vitro digestion

Broad bean can be processed into various forms such as steamed broad beans (SBB) and broad bean natto (BBN), with potential variations in their nutritional profiles upon digestion. This study aimed to explore the differences in phenolic content, composition, and antioxidant activity between SBB and BBN during simulated in vitro digestion. Findings demonstrated that BBN exhibited a significant surge in total phenolic and flavonoid contents post-gastrointestinal digestion compared to SBB. UHPLC-MS/MS analyses identified major phenolic compounds in BBN including protocatechuic acid and p-hydroxybenzoic acid and key flavonoids like luteolin and catechins. P-hydroxybenzoic acid and catechins underwent significant changes throughout the digestion. Furthermore, BBN's antioxidant activity was higher than that of SBB after digestion, with superior DPPH, ABTS +center dot scavenging abilities, and FRAP reducing power. A correlation emerged between antioxidant activity and phenolic contents, notably with p-hydroxybenzoic and benzoic acids. BBN's digestive stage exhibited superior polyphenol release and antioxidant capacity than SBB, offering insights into polyphenol-rich food consumption. The TPC and TFC of the SBB and BBN were significantly increased by simulating in vitro digestion, and the effects of digestion on the different samples were different.dagger image