Influence of polyphenol oxidase, peroxidase and organic acids on the in vitro iron bioavailability in faba bean flour

Abstract

Dephytinized faba bean flour was incubated with crude extracts from pear, banana, or apple, respectively, followed by investigation of the impacts on the phenolic content and on in vitro iron bioavailability. Incubation with crude extracts resulted in significant reduction of phenolic compounds in faba bean flour. The largest reduction in phenolic compounds (51.0%) was obtained after incubation with apple extract, as well as the highest amount of in vitro iron bioavailability (68.6%), with banana extract being almost as effective (42.1% reduction). Incubation with pear or banana extract increased in 14.1% and 22.2% the in vitro iron bioavailability. Peroxidase activity and some organic acids in the fruit extracts might also have contributed to the positive effect on in vitro iron bioavailability. The results from this study suggest that the polyphenol oxidase activity in simple fruit extracts can be utilized to increase the in vitro iron bioavailability in dephytinized polyphenol-containing legume foods.