Location: Plant, Soil and Nutrition Research2012 Annual Report
1a. Objectives (from AD-416):
This project seeks to produce lentils that are biofortified with iron (Fe). To do so, this project contains two major components; 1) a “fast track” approach of identifying current harvests and possible cultivars of high Fe lentils already in use by growers; and 2) to begin a longer term strategy to understand the high Fe concentration and bioavailability traits in lentils and create new varieties with enhanced Fe nutritional quality.
1b. Approach (from AD-416):
To accomplish the first objective, we will partner with Simpson Seeds (Moose Jaw, SK) to sample and track incoming shipments of lentils through the processing facility. Samples of the incoming shipments will be analyzed for Fe concentration (via inductively coupled plasma emission spectroscopy) and Fe bioavailability using a bioassay that combines simulated gastric and intestinal digestion with Fe uptake by human intestinal epithelial cells (Glahn et al., J. Nutr. 1998, 128:1555-1561; Yun et al., J. Nutr. 2004, 134:2717 – 2721). From these studies we expect to document the range of Fe concentration and bioavailability in samples of particular varieties during a given harvest period and to correlate that information with soil type, location and weather. Samples that are identified as promising via the bioassay will be confirmed with an animal study (ie. a poultry model; Tako et al., Poultry Sci. 2010, 89:514-521) to confirm the bioassay results and demonstrate proof of concept. For the second objective, we will utilize the above-mentioned techniques as screening tools to search through mapping populations of lentils and identify the molecular markers associated with Fe bioavailability and concentration. This approach has recently been shown to be feasible in maize (Lung’aho et al., submitted; Hoekenga et al., 2011 Plant Gen Res in press) and should result in a breeding approach that allows sustainable enhancement of Fe nutritional quality.
3. Progress Report:
Lentils are a staple food crop that are relatively high in Fe concentration compared to grains such as rice, wheat and maize. In Bangladesh and India, regions of the world where Fe deficiency anemia is high, increased consumption of lentils could provide a significant amount of dietary Fe that could alleviate iron deficiency anemia. Lentil growers in Saskatchewan, Canada, export significant amounts to Bangladesh and India; therefore, we have a unique situation where farmers utilizing modern agriculture are producing a crop capable of reducing iron deficiency anemia and are willing to invest in research to demonstrate and enhance these potential nutritional benefits. Approximately 20-25 samples from a recent harvest of lentils were collected at a lentil processing facility in Moose Jaw, Canada, and sent to the Glahn lab at the Robert W. Holley Center for Agriculture and Health in Ithaca, NY for Fe concentration and bioavailability analysis. This screening of samples enables us to see the range of diversity that could occur in a single season of lentil production in this region. Based on previous experience, we expected that some of these harvests to be higher in Fe concentration and bioavailability relative to others. In previous work, we observed that some harvests are essentially “biofortified” and are nutritionally superior; however, we did not have a broad enough sampling from within a single harvest season. Therefore, our initial goal was to document these differences in Fe concentration and bioavailability using our cell culture model and then confirm these differences via an animal feeding trial. By confirming these measurements in an animal feeding trial we are demonstrating the effectiveness of our screening tools for this crop and demonstrating that more nutritious. At present, the in vitro screening is complete and diets are in preparation for animal feeding trials in September 2012. The recent in vitro screening has clearly identified harvests of lentils that are superior in terms of Fe bioavailability relative to other harvests. An added dimension to this research is that it enables us to prepare for a large scale human feeding trial planned for Bangladesh. This research essentially demonstrates how the material for this human study should be identified and prepared for the human trial. In a smaller study within the above research, we have clearly demonstrated that removal of the lentil hull significantly improves Fe bioavailability from the lentil. We believe this is due to the presence of polyphenolics in the seed coat, an effect that is seen in other legumes such as beans. Our research indicates that this is good news for red lentils as they as primarily consumed dehulled, however most green lentils are consumed with the hulls intact. Our research also indicates that a more complete understanding of the seed coat polyphenolic effects on Fe bioavailability is warranted.