Impact of dietary components and processing on mineral bioaccessibility and bioavailability in Iron-biofortified...

Micronutrient deficiencies (MNDs), particularly involving essential minerals, are often associated with their insufficient intake as well as limited bioavailability due to the influence of antinutritional factors (ANFs) and processing effects. This study assessed the impact of processing (boiling and fermentation) on total phenolic content (TPC), total dietary fiber (TDF), bioaccessibility and bioavailability of Fe, Zn, Cu, Ca, S and Mg in Fe-biofortified lentils using an in vitro model. To evaluate Fe bioavailability, ferritin formation was measured using the Caco-2 cell bioassay. Fermented lentil flour (FLF) presented the highest TPC (331.3 mg/100 g) and lowest TDF content (20.1%). Among the minerals, Fe bioaccessibility was highest in FLF (76.1%), while Cu (99.0%), Zn (62.6%), Ca (60.2%), Mg (22.9%) and S (22.6%) bioaccessibility were higher in boiled lentil flour (BLF). In vitro bioavailability results showed that Fe (69.4%) and Ca (50.3%) were most bioavailable in FLF, whereas Zn (52.3%), Cu (81.2%), S (17.0%) and Mg (20.1%) showed higher bioavailability in BLF. Caco-2 cell ferritin formation supported these findings, with the highest levels recorded in FLF (14.7 ng ferritin/mg protein) followed by BLF. Correlation analysis revealed a positive association between bioaccessible and bioavailable Fe with Zn, Cu, and Mg, while exhibiting a negative correlation with S. Ca showed varied relationships, a strong negative correlation with Fe in BLF, moderate positive correlation in RLF, and strong positive correlation in FLF. Overall, this study demonstrates that common processing methods considerably influence the bioaccessibility and bioavailability of minerals in Fe-biofortified lentils.