Fermentation and Lactic Acid Addition Enhance Iron Bioavailability of Maize

Abstract

Maize is one of the most important cereal crops for human consumption, yet it is of concern due to its low iron bioavailability. The objective of this study was to determine the effects of processing on iron bioavailability in common maize products and elucidate better processing techniques for enhancing iron bioavailability. Maize products were processed to represent different processing techniques: heating (porridge), fermentation (ogi), nixtamalization (tortillas), and decortication (arepas). Iron and phytate contents were evaluated. Iron bioavailability was assessed using the Caco-2 cell model. Phytate content of maize products was significantly reduced by decortication (25.6%, p ) 0.003) and nixtamalization (15%, p ) 0.03), and iron content was reduced by decortication (29.1%, p ) 0.002). The relative bioavailability (RBA, compared to 100% bioavailability of porridge with FeSO4) of ogi was significantly higher than that of other products when fortified with FeSO4 (p < 0.001) or reduced iron (p < 0.001). Addition of lactic acid (6 mg/g of maize) significantly increased iron solubility and increased bioavailability by about 2-fold (p < 0.01), especially in tortillas. The consumer panel results showed that lactic acid addition does not significantly affect the organoleptic characteristics of tortillas and arepas (p ) 0.166 and 0.831, respectively). The results suggest that fermentation, or the addition of small amounts of lactic acid to unfermented maize products, may significantly improve iron bioavailability. Lactic acid addition may be more feasible than the addition of highly bioavailable but expensive fortificants. This approach may be a novel means to increase the iron bioavailability of maize products to reduce the incidence of iron deficiency anemia.

Effect of dephytinization on bioavailability of iron, calcium and zinc from infant cereals assessed in the Caco-2 cell model

“…It should be noted that the positive correlation observed between iron solubility with cell transport and uptake efficiencies percentages found in our study is in agreement with Bergqvist et al [26] , studying iron absorption from carrot juice, and with Proulx and Reddy [32] studying iron bioavailability of maize, both using Caco-2 cells. Meanwhile, it has been reported by other authors [27,33] that solubility and bioavailability by Caco-2 cells did not show parallel trends.…”

Almond milk fermented with different potentially probiotic bacteria improves iron uptake by intestinal epithelial (Caco-2) cells

“…In particular, samples fermented with L. rhamnosus, with either B. bifidum (F8) or B. longum (F9), were the ones which induced the most iron uptake (p< 0.05). Previous studies have also shown the in vitro enhancing effect of probiotic bacteria on iron uptake in fermented vegetable matrices, such as carrot juice (Bergqvist, Andlid, & Sandberg, 2006), maize (Proulx & Reddy, 2007) or beans (Laparra, Tako, Glahn, & Miller, 2008). This study, hence, extends the bacterialmediated positive effects on iron uptake from fermented vegetable products, particularly those in which the starter culture contains bifidobacteria strains.…”

Role of Antioxidant Enzymes in Bacterial Resistance to Organic Acids

“…It has been shown that lactate stimulates fibroblast proliferation (62) and wound healing (59), enhances iron bioavailability in foods (45), and increases iron absorption by the human colon carcinoma cell line (Caco-2 cells) (10). Furthermore, lactic acid has been shown to chelate Fe 3ϩ in a 1:1 ratio (29), and that lactate-iron complex can generate hydroxyl radicals (2).…”