Iron accumulation and partitioning in hydroponically grown wild and cultivated chickpea (Cicer arietinum L).

Chickpea (Cicer arietinum L.) is a staple food in many developing countries where iron (Fe) deficiency often occurs in their population. The crop is a good source of protein, vitamins, and micronutrients. Fe biofortification in chickpea can be part of long-term strategy to enhance Fe intake in human diet to help to alleviate Fe deficiency. To develop cultivars with high Fe concentration in seeds, understanding the mechanisms of absorption and translocation of Fe into the seeds is critical. An experiment was conducted using a hydroponic system to evaluate Fe accumulation in seeds and other organs at different growth stages of selected genotypes of cultivated and wild relatives of chickpea. Plants were grown in media with Fe zero and Fe added conditions. Six chickpea genotypes were grown and harvested at six different growth stages: V3, V10, R2, R5, R6, and RH for analysis of Fe concentration in roots, stems, leaves, and seeds. The relative expression of genes related to Fe-metabolism including FRO2, IRT1, NRAMP3, V1T1, YSL1, FER3, GCN2, and WEE1 was analyzed. The results showed that the highest and lowest accumulation of Fe throughout the plant growth stages were found in the roots and stems, respectively. Results of gene expression analysis confirmed that the FRO2 and IRT1 were involved in Fe uptake in chickpeas and expressed more in roots under Fe added condition. All transporter genes: NRAMP3, V1T1, YSL1 along with storage gene FER3 showed higher expression in leaves. In contrast, candidate gene WEE1 for Fe metabolism expressed more in roots under Fe affluent condition; however, GCN2 showed over-expression in roots under Fe zero condition. Current finding will contribute to better understanding of Fe translocation and metabolism in chickpea. This knowledge can further be used to develop chickpea varieties with high Fe in seeds.

Quantitative trait loci associated with amino acid concentration and in vitro protein digestibility in pea (Pisum sativum L.).

With the expanding interest in plant-based proteins in the food industry, increasing emphasis is being placed on breeding for protein concentration and quality. Two protein quality traits i.e., amino acid profile and protein digestibility, were assessed in replicated, multi-location field trials from 2019 to 2021 in pea recombinant inbred line population PR-25. This RIL population was targeted specifically for the research of protein related traits and its parents, CDC Amarillo and CDC Limerick, had distinct variations in the concentration of several amino acids. Amino acid profile was determined using near infrared reflectance analysis, and protein digestibility was through an in vitro method. Several essential amino acids were selected for QTL analysis, including lysine, one of the most abundant essential amino acids in pea, and methionine, cysteine, and tryptophan, the limiting amino acids in pea. Based on phenotypic data of amino acid profiles and in vitro protein digestibility of PR-25 harvested in seven location-years, three QTLs were associated with methionine + cysteine concentration, among which, one was located on chromosome 2 (R2 = 17%, indicates this QTL explained 17% phenotypic variation of methionine + cysteine concentration within PR-25), and two were located on chromosome 5 (R2 = 11% and 16%). Four QTLs were associated with tryptophan concentration and are located on chromosome 1 (R2 = 9%), chromosome 3 (R2 = 9%), and chromosome 5 (R2 = 8% and 13%). Three QTLs were associated with lysine concentration, among which, one was located on chromosome 3 (R2 = 10%), the other two were located on chromosome 4 (R2 = 15% and 21%). Two QTLs were associated with in vitro protein digestibility, one each located on chromosomes 1 (R2 = 11%) and 2 (R2 = 10%). QTLs associated with in vitro protein digestibility, and methionine + cysteine concentration on chromosome 2 were identified to be co-localized with known QTL for total seed protein concentration in PR-25. QTLs associated with tryptophan and methionine + cysteine concentration co-localized on chromosome 5. The identification of QTLs associated with pea seed quality is an important step towards marker-assisted selection of breeding lines with improved nutritional quality, which will further boost the competitiveness of pea in plant-based protein markets.

Iron Fortification and Bioavailability of Chickpea (Cicer arietinum L.) Seeds and Flour.

Iron (Fe) deficiency is one of the most common nutritional disorders, and is mainly due to insufficient intake of bioavailable Fe. Chickpea (Cicer arietinum L.) was examined as a potential vehicle for Fe fortification. Fortificants (FeSO4·7H2O (ferrous sulfate hepta-hydrate), FeSO4·H2O (ferrous sulfate mono-hydrate) and NaFeEDTA (ethylenediaminetetraacetic acid iron (iii) sodium salt)) were applied by a spraying and drying method. At 2000 µg g-1 iron fortificant, the fortified split desi seeds (dal), desi flour and kabuli flour supplied 18-19 mg, 16-20 mg and 11-19 mg Fe per 100 g, respectively. The overall consumer acceptability using a nine-point hedonic scale for sensory evaluation demonstrated that NaFeEDTA-fortified cooked chickpea (soup and chapatti) scored the highest among the three fortificants. Lightness (L*), redness (a*) and yellowness (b*) of Fe-fortified products changed over time. However, no organoleptic changes occurred. Fe bioavailability was increased by 5.8-10.5, 15.3-25.0 and 4.8-9.0 ng ferritin mg-1 protein for cooked split desi seeds (soup), desi chapatti and kabuli chapatti, respectively, when prepared using Fe-fortified chickpea. Desi chapatti showed significantly higher Fe bioavailability than the other two. The increase in Fe concentration and bioavailability in fortified chickpea products demonstrated that these products could provide a significant proportion of the recommended daily Fe requirement.

Sensory Acceptability of Iron-Fortified Red Lentil (Lens culinaris Medik.) Dal.

Panelists in Saskatoon, Canada (n = 45) and Dhaka, Bangladesh (n = 98) participated in sensory evaluations of the sensory properties of both cooked and uncooked dehulled red lentil dal fortified with FeSO4 ·7H2 O, NaFeEDTA or FeSO4 ·H2 O at fortificant Fe concentrations of 800, 1,600 (both cooked and uncooked), or 2,800 ppm. Appearance, odor, and overall acceptability of cooked and uncooked samples were rated using a 9-point hedonic scale (1 = dislike extremely to 9 = like extremely). Taste and texture were rated for the cooked samples prepared as typical south Asian lentil meals. Significant differences in sensory quality were observed among all uncooked and cooked samples at both locations. Overall, scores for all sensory attributes and acceptability of uncooked lentil decreased with increasing concentration of Fe in the fortificant; however, Fe fortification (particularly with NaFeEDTA) had small effects on acceptability. Panelists from Saskatoon provided a wider range of scores than those from Bangladesh for all attributes of cooked lentil. Overall, sensory evaluation of Fe fortification using NaFeEDTA minimally affected consumer perception of color, taste, texture, odor, and overall acceptability of cooked lentil. Reliability estimates (Cronbach's alpha [CA]) indicated that consumer scores were generally consistent for all attributes of all lentil samples (mean CA > 0.80). NaFeEDTA was found to be the most suitable Fe fortificant for lentil based on consumer acceptability. Consumption of 45 to 50 g of NaFeEDTA-fortified lentil (fortificant Fe concentration of 1,600 ppm) per day meets the estimated average requirements (EARs) of Fe for humans (10.8 to 29.4 mg). PRACTICAL APPLICATION: Iron fortification of dehulled lentil dal may change organoleptic attributes that can influence consumer acceptability. Sensory evaluation by consumers helps to determine the effect on appearance, odor, taste, texture, and overall acceptability of fortified lentils. In this study, consumer acceptability was evaluated with panelists who consume lentil regularly. Panelists provided significantly different scores for 5 sensory attributes for 10 uncooked and 3 cooked lentil samples. Panelists reliably preferred NaFeEDTA as the most suitable Fe fortificant for dehulled lentils for 5 attributes. Overall, lentil dal fortified with NaFeEDTA can offer a simple and low-cost solution to human health problems associated with iron-related malnutrition.

Iron Fortification of Lentil (Lens culinaris Medik.) to Address Iron Deficiency.

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.

Genetic diversity and association mapping of iron and zinc concentrations in chickpea (Cicer arietinum L.).

Chickpea (Cicer arietinum L.) is the world's second most important pulse crop after common bean. Chickpea has historically been an important daily staple in the diet of millions of people, especially in the developing countries. Current chickpea breeding programs have mainly been directed toward high yield, biotic and abiotic stress resilience that has increased global production, but less attention has been directed toward improving micronutrient concentrations in seeds. In an effort to develop micronutrient-dense chickpea lines, a study to examine the variability and to identify SNP alleles associated with seed iron and zinc concentrations was conducted using 94 diverse accessions of chickpea. The results indicated that there is substantial variability present in chickpea germplasm for seed iron and zinc concentrations. In the current set of germplasm, zinc is negatively correlated with grain yield across all locations and years; whereas the negative correlation between iron and grain yield was only significant at the Elrose locality. Eight SNP loci associated with iron and (or) zinc concentrations in chickpea seeds were identified. One SNP located on chromosome 1 (chr1) is associated with both iron and zinc concentrations. On chr4, three SNPs associated with zinc concentration and two SNPs for iron concentration were identified. Two additional SNP loci, one on chr6 and the other on chr7, were also found to be associated with iron and zinc concentrations, respectively. The results show potential opportunity for molecular breeding for improvement of seed iron and zinc concentrations in chickpea.