Dual-Fortified Lentil Products-A Sustainable New Approach to Provide Additional Bioavailable Iron and Zinc in Humans

Rajib Podder; Raymond P Glahn; Albert Vandenberg

doi:10.1093/cdn/nzab004

Dual-Fortified Lentil Products-A Sustainable New Approach to Provide Additional Bioavailable Iron and Zinc in Humans

Curr Dev Nutr. 2021 Jan 30;5(2):nzab004. doi: 10.1093/cdn/nzab004. eCollection 2021 Feb.

Authors

Rajib Podder¹, Raymond P Glahn², Albert Vandenberg¹

Affiliations

¹ Department of Plant Sciences, University of Saskatchewan, Saskatoon, Canada.
² Robert W Holley Center for Agriculture and Health, Agricultural Research Service, USDA, Ithaca, NY, USA.

Abstract

Background: Iron (Fe) and zinc (Zn) deficiencies are global health problems affecting 20% and 33% of the world's population, respectively. Lentil (Lens culinaris Medik.), part of the staple food supply in many countries, can be a potential vehicle for Fe and Zn fortification.

Objective: We developed a dual-fortification protocol to fortify 3 milled lentil product types (LPTs) [red-football (RF), red-split (RS), and yellow-split (YS)], with NaFeEDTA and ZnSO₄.H₂O to increase the bioavailable content of Fe and Zn.

Methods: Appropriate Fe and Zn doses were determined to fortify lentils based on RDAs. Relative Fe bioavailability (RFeB%) and phytic acid (PA) content were assessed using an in vitro Caco-2 cell bioassay and PA analysis, respectively. One-factor ANOVA determined the differences in colorimetric score; concentrations of Fe, Zn, and PA; and RFeB% among samples. The least significant difference was calculated with significance level set at P < 0.05.

Results: Fe and Zn concentration and RFeB% increased and PA concentration decreased significantly in dual-fortified lentils. Dual-fortified lentil samples had higher RFeB% compared with Fe-fortified (single) samples in all 3 LPTs, whereas RFeB% decreased in Zn-fortified (single) RF and YS samples by 43.4% and 36%, respectively. The RF, RS, and YS samples, fortified with 16 mg Fe and 8 mg Zn/100 g of lentils, provided 27 mg Fe and 14 mg Zn, 28 mg Fe and 13.4 mg Zn, and 29.9 mg Fe and 12.1 mg Zn, respectively. RFeB% of RF, RS, and YS lentil samples increased by 91-307%, 114-522%, and 122-520%, respectively. Again, PA concentrations of RF, RS, and YS lentils were reduced by 0.63-0.53, 0.83-0.71, and 0.96-0.79 mg/g, respectively.

Conclusions: Dual-fortified lentil consumption can cost-effectively provide a significant part of the daily bioavailable Fe and Zn requirements of people with these 2 globally important micronutrient deficiencies.

Keywords: bioavailability; fortification; iron; phytic acid; zinc.