Influence of polyphenol oxidase, peroxidase and organic acids on thein vitroiron 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.

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“…On the other hand, two of the main enzymes related with fruit browning, are polyphenol oxidase (PPO) and peroxidase (POD) (Luo and Xie, 2012). No published reports were found on the relationship of the activity of these enzymes and the browned flesh of MS that could be observed in fruit at consumption maturity or at over ripened fruit.…”

“…La PPO cataliza la conversión de fenoles a o-difenoles a través de la hidroxilación y conversión de o-hidroxifenoles a o-quinonas por medio de la oxidación, lo que resulta en oscurecimiento del tejido vegetal (Aydemir, 2004). La POD es otra enzima oxidoreductasa involucrada en el pardeamiento de tejido vegetal, ya que también oxida difenoles como sustrato (Mdluli, 2005), y podría actuar sinérgicamente con la PPO debido a la formación de peróxido de hidrógeno durante la actividad oxidativa de la PPO (Luo & Xie, 2012).…”

“…PPO catalyzes the conversion of phenols to o-diphenols through hydroxylation and conversion of o-dihydroxyphenols to o-quinones through oxidation, resulting in browning of plant tissue (4). POD is another oxidoreductase enzyme involved in plant tissue browning, since it also oxidizes diphenols as substrates (Mdluli, 2005), and could act synergistically with PPO due to formation of hydrogen peroxide during the PPO oxidation activity (Luo & Xie, 2012).…”

“…Por otro lado, la polifenol oxidasa (PPO) y la peroxidasa (POD) son dos de las principales enzimas relacionadas con el pardeamiento de la fruta (Luo and Xie, 2012). No se encontraron informes publicados sobre la relación de la actividad de estas enzimas y el pardeamiento de la pulpa que se puede observar en el fruto maduro o muy maduro de zapote mamey.…”