Effect of solid-state fermentation on mineral binding efficiency of chickpea protein: Characterization and in-vitro mineral uptake

Iron deficiency is a prevalent global health concern, especially in populations lacking diverse nutrient sources. Chickpeas, rich in both protein and iron, face limitations in iron bioavailability due to anti-nutritional factors and low iron complex solubility. In this regard, solid-state fermentation offers promise in enhancing plant-based food nutrition. Therefore, this study examined the impact of fermentation on chickpea protein's mineral binding, focusing on iron complexation. Comparing native chickpea protein-iron complex (NCP-Fe) and fermented chickpea protein-iron complex using Aspergillus awamori (FCP90-Fe), significant improvements were noted after 90 h of fermentation. Protein content and solubility in FCP90-Fe increased by 14.77 % and 22.70 %, respectively. Structural alterations induced by A. awamorai were evident through Fourier transform infrared spectroscopy and thermogravimetric analysis. Functional attributes such as protein solubility (18.91 %), oil (23.60 %), and water holding capacity (19.17 %) also improved in FCP90-Fe, indicating enhanced food application potential. Additionally, FCP90-Fe exhibited a 31.74 % increase in iron content and significantly higher mineral bioavailability, with enhancements of 21.99 % and 59.90 % compared to NCP-Fe. In vitro studies demonstrated increased iron transportation, retention, and uptake by 11.07 %, 10.42 %, and 7.09 %, respectively, underscoring improved iron bioavailability from fermented chickpea protein. Moreover, FCP90-Fe notably elevated ferritin synthesis levels, suggesting enhanced iron storage capacity within cells, with a 62.66 % increase in ferritin content per mg cell protein and a 39.59 % increase per gram sample compared to NCP-Fe. This study emphasizes the considerable impact of fermentation on the chickpea protein iron complex. It increases its mineral bioavailability, iron uptake, digestibility, and mineral bioavailability.