Iron and zinc fortified lentil (Lens culinaris Medik.) demonstrate enhanced and stable iron bioavailability after storage

Authors: PODDER, RAJIB - University Of Saskatchewan; Glahn, Raymond; VANDENBERG, ALBERT - University Of Saskatchewan

Submitted to: Frontiers in Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/24/2020
Publication Date: 1/8/2021
Citation: Podder, R., Glahn, R.P., Vandenberg, A. 2021. Iron and zinc fortified lentil (Lens culinaris Medik.) demonstrate enhanced and stable iron bioavailability after storage. Frontiers in Nutrition. 7:614812. https://doi.org/10.3389/fnut.2020.614812.
DOI: https://doi.org/10.3389/fnut.2020.614812

Interpretive Summary: Lentils are rich in minerals, such as iron (Fe) and zinc (Zn), relative to grains such as wheat and maize. However, due to low consumption rate in daily diet, lentils fortified with Fe and Zn have been developed to provide a significant bioavailable Fe and Zn for populations at risk of deficiency of these minerals. Assessment of storage stability is essential for this product. Therefore, in the current study, three milled lentil product types - red football, red split, yellow split (that had been fortified with different doses of Fe), were assessed for nutritional quality of Fe at initial formation and after 1 year of storage. Results showed that the lentil products retained nutritional quality of Fe after 1 year in storage; thus, the products can be expected to have the necessary shelf life to deliver significant Fe and Zn to populations at risk of deficiency.

Technical Abstract: Lentil (Lens culinaris Medik) is rich in minerals, such as iron (Fe) and zinc (Zn), but due to lower bioavailability and low consumption rate in daily diet, dual-fortified lentil with Fe and Zn can provide a significant bioavailable Fe and Zn. In current study, three milled lentil product types (LPTs), red football (RF), red split (RS), yellow split (YS) were fortified with different doses of Fe from NaFeEDTA (Fe-fortified) or Zn from ZnSO4.H2O (Zn-fortified) or both (dual-fortified). Fe, Zn, phytic acid (PA) concentration and relative Fe bioavailability (RFeB%) were assessed for samples from two batches (initial and for one-year stored). Overall, Fe, Zn and RFeB% were increased significantly in two batches samples from three LPTs with the increase of Fe and Zn doses but decreased 5-15% after one year of storage. PA concentration was decreased from 8-15% after fortification in all samples from two batches of three LPTs but showed a different pattern of influence of storage time on PA concentration. Dual-fortified lentil fortified with 24 mg Fe and 12 mg Zn 100-1g lentil got the highest amount of Fe, Zn but lowest amount of PA concentration, and RFeB% was increased from 91.3 to 519.5% at initial batch. A significant (p = 0.01) Pearson correlation was observed between Fe concentration vs. PA:Fe molar ratio (MR), Fe concentration vs. RFeB%, RFeB% vs. PA:Fe MR, and Zn concentration vs. PA:Zn MR. In conclusion, dual-fortified lentil can contribute significant bioavailable Fe and Zn to populations at risk of Fe and Zn deficiency.