Lens culinaris Medik. ssp. culinaris is the only cultivated species in the genus Lens. Intensive selection pressure to develop new cultivars, a narrow genetic base, co-evolution of pathogens to partially resistant cultivars and other factors have accelerated susceptibility to different fungal diseases in this species. Few sources for resistance to stemphylium blight (SB) caused by Stemphylium botryosum Wallr. exist among commercial lentil cultivars. A total of 70 accessions were selected from seven species of the genus Lens to screen for SB resistance. The L. culinaris accessions were screened in four different environments, and the accessions of Lens ervoides, L. culinaris ssp. orientalis, Lens tomentosus,Lens nigricans, Lens odemensis and Lens lamottei in growth chamber or greenhouse experiments to identify resistance sources for potential use in lentil breeding. A highly aggressive isolate of SB was used as an inoculum to screen them under controlled conditions. Lentil cultivars ‘Eston’ (resistant) and ‘CDC Glamis’ (susceptible) were used as checks with consistent results in all experiments. Most of the L. culinaris accessions were susceptible to SB, whereas more than 70% of the wild lentil accessions had disease severity scores equal to or significantly lower than that of the SB-resistant check ‘Eston’. Some wild species accessions previously identified with resistance to anthracnose (Colletotrichum truncatum) and ascochyta blight (Ascochyta lentis) were also highly resistant to SB. The highest frequency of resistance to SB was found in L. lamottei followed by L. ervoides of the secondary gene pool. These sources can potentially be used to develop new commercial cultivars with multiple or single disease resistance.

Iron (Fe) deficiency is a major human health concern in areas of the world in which diets are often Fe deficient. In the current study, we aimed to identify appropriate methods and optimal dosage for Fe fortification of lentil (Lens culinaris Medik.) dal with FeSO₄·7H₂O (ferrous sulphate hepta-hydrate), NaFeEDTA (ethylenediaminetetraacetic acid iron (III) sodium salt) and FeSO₄·H₂O (ferrous sulphate mono-hydrate). We used a colorimetric method to determine the appearance of the dal fortified with fortificants at different Fe concentrations and under different storage conditions. Relative Fe bioavailability was assessed using an in vitro cell culture bioassay. We found that NaFeEDTA was the most suitable fortificant for red lentil dal, and at 1600 ppm, NaFeEDTA provides 13–14 mg of additional Fe per 100 g of dal. Lentil dal sprayed with fortificant solutions, followed by shaking and drying at 75 °C, performed best with respect to drying time and color change. Total Fe and phytic acid concentrations differed significantly between cooked unfortified and fortified lentil, ranging from 68.7 to 238.5 ppm and 7.2 to 8.0 mg g⁻¹, respectively. The relative Fe bioavailability of cooked fortified lentil was increased by 32.2–36.6% compared to unfortified cooked lentil. We conclude that fortification of lentil dal is effective and could provide significant health benefits to dal-consuming populations vulnerable to Fe deficiency.

Due to low Fe bioavailability and low consumption per meal, lentil must be fortified to contribute significant bioavailable Fe in the Bangladeshi diet. Moreover, since red lentil is dehulled prior to consumption, an opportunity exists at this point to fortify lentil with Fe. Thus, in the present study, lentil was Fe-fortified (using a fortificant Fe concentration of 2800 µg g⁻¹) and used in 30 traditional Bangladeshi meals with broad differences in concentrations of iron, phytic acid (PA), and relative Fe bioavailability (RFeB%). Fortification with NaFeEDTA increased the iron concentration in lentil from 60 to 439 µg g⁻¹ and resulted in a 79% increase in the amount of available Fe as estimated by Caco-2 cell ferritin formation. Phytic acid levels were reduced from 6.2 to 4.6 mg g⁻¹ when fortified lentil was added, thereby reducing the PA:Fe molar ratio from 8.8 to 0.9. This effect was presumably due to dephytinization of fortified lentil during the fortification process. A significant (p ≤ 0.01) Pearson correlation was observed between Fe concentration and RFeB% and between RFeB% and PA:Fe molar ratio in meals with fortified lentil, but not for the meal with unfortified lentil. In conclusion, fortified lentil can contribute significant bioavailable Fe to populations at risk of Fe deficiency.

Lentil (Lens culinaris Medik.) is a quick-cooking, rapidly expanding protein-rich crop with high iron (Fe) and zinc (Zn), but low bioavailability due to the presence of phytate, similar to other grains. Lentils dual fortified with Fe and Zn can significantly improve the bioavailable Fe and Zn content. Three milled lentil product types (LPTs) were fortified with Fe using NaFeEDTA [ethylenediaminetetraacetic acid iron (III) sodium salt] (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 fortified batches (initial and for 1 year stored). Fe, Zn, and RFeB% increased significantly in two batches of samples from the three LPTs, and decreased by 5–15% after 1 year of storage. PA concentration decreased from 8 to 15% after fortification of all samples from two batches of the three LPTs but showed different patterns of influence after storage. Dual-fortified lentil fortified with 24 mg Fe and 12 mg Zn 100 g⁻¹ lentil had the highest amount of Fe and Zn, and the lowest PA concentration, and RFeB% was increased from 91.3 to 519.5%. Significant (p ≤ 0.01) Pearson correlations were 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 all samples from two batches of the three LPTs. In conclusion, dual-fortified lentil can contribute significant bioavailable Fe and Zn to populations at risk of Fe and Zn deficiency.

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. 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. 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. 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. 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.