Seed coat removal of red lentils enhances iron bioavailability in traditional Bangladeshi meals

Abstract

Iron (Fe) deficiency is the most prevalent nutrient deficiency in the world, a major cause of which is a lack of highly bioavailable dietary Fe. Lentils (Lens culinaris) are a pulse crop consumed world‐wide, and are higher in bioavailable Fe compared to other legumes. We screened numerous meal combinations (n=46) for Fe concentration and relative Fe bioavailability using the in vitro digestion/Caco‐2 cell model. Traditional Bangladeshi dal was prepared with either dehulled (seed coat removed) or whole red lentil (seed coat intact). Other components of the meals included Basmati rice, vegetable curry, and steamed fish. Fe concentration of the mixed meals ranged from 4.8 – 65.0 ppm Fe. We observed a two‐fold increase in iron bioavailability in recipes containing dehulled lentil (p<0.001). Fe concentration and relative bioavailability were significantly correlated in the meals containing the dehulled lentil (r=0.52, p=0.01), but not in those containing whole lentil (r=−0.35, p=0.11). Since most red lentils are consumed with the seed coat removed, this class of lentils has potential to be a significant source of dietary Fe. These experiments highlight the need to improve our understanding of the effect of seed coat polyphenolics on Fe biovailability. Funded by the Saskatchewan Pulse Growers and USDA‐ARS.