Location: Plant, Soil and Nutrition Research
2023 Annual Report
Objectives
Objective 1: In collaboration with plant breeders, utilize in vitro, in vivo, and analytical techniques to evaluate Fe bioavailability in staple food crops (beans, wheat, maize) for the purpose of developing crops that serve as an improved source of Fe. [NP107, C1, PS1A]
Sub-objective 1.A. Collaborate with breeders to develop bean varieties with enhanced Fe bioavailability that can deliver more absorbable Fe and be a highly sustainable source of dietary Fe.
Sub-objective 1.B. Characterize the potential genotype x environment (GxE) interactions that influence Fe content and Fe bioavailability in beans; and determine if either content, bioavailability or both can be sustainable approaches to improve Fe nutrition from beans.
Sub-objective 1.C. Collaborate with breeders to characterize Fe bioavailability and Fe concentration from the different components of the maize and wheat grain, and search for QTL for enhanced Fe bioavailability and content of these components.
Objective 2. Characterize the individual and interactive effects of dietary minerals (Fe and Zn), phytochemicals and prebiotics common to staple foods (chickpea, bean, wheat, lentil) on the intestinal microbiome and intestinal brush border membrane functionality. [NP107, C3, PS3B]
Sub-objective 2.A. Evaluate the effect of natural prebiotics and phytochemicals extracted from staple food crops on mineral (Fe, Zn) dietary bioavailability and absorption in vivo (Gallus gallus).
Approach
As iron and zinc deficiencies are affecting approximately 30% of the world’s populations, including about 15% of the US population, the focus of this research plan is to improve iron bioavailability in staple food crops and to further increase their consumer appeal. Further, we aim to characterize the individual and interactive effects of dietary minerals (Fe and Zn), phytochemicals and prebiotics common to staple foods (chickpea, bean, wheat, lentil) on the intestinal microbiome and intestinal brush border membrane functionality. This will be done in order to evaluate the effect of natural prebiotics and phytochemicals extracted from staple food crops on mineral (Fe, Zn) dietary bioavailability and absorption in vivo (Gallus gallus). In addition, as the newly accepted body “organ”, the intestinal microbiome plays a vital role in the functionality, absorption and digestion capabilities of the intestine; hence, we aim to characterize the microbiome response to dietary plant origin bioactive compounds that may contribute to intestinal functionality and overall health. To accomplish the above, we will employ our established screening tools of an iron bioavailability bioassay and a poultry model that reflects human nutrition. In conjunction, we will make use of techniques such as mass spectroscopy, marker assisted molecular breeding, our Zinc Status biomarker, gene expression, microscopy, and state of the art microbial profiling techniques. With this unique combination of tools, we expect to develop staple food crops with enhanced iron nutrition and elucidate factors that can improve zinc nutrition from staple food crops, and thereby contribute to alleviation of two of the leading micronutrient deficiencies in the world. We will also expand knowledge of how the intestinal microbiome is affected by dietary iron, zinc, phytochemicals and prebiotics. Overall, this knowledge will further contribute to food innovations with enhanced nutrition and improve human health both domestically and abroad.
Progress Report
Supporting International Breeding Programs by Developing Fast Cooking Dry Beans with Improved Iron Nutrition. As in previous years, research on beans, specifically the yellow bean market class was a major focus of this fiscal year. This research continues to identify fast cooking bean varieties that provide enhanced Fe nutrition. A germplasm screening of several hundred commercial lines, biofortified varieties and breeding lines from Africa (Uganda, Zambia, Ghana and Tanzania) and Central America (Guatemala, Honduras and Costa Rica) are currently being conducted to measure the cooking time, mineral content and iron bioavailability of their most useful breeding material. In addition, the USDA-ARS has provided their Andean and Yellow bean diversity collections to these nations for breeding and evaluation. The collaboration between the USDA-ARS and international breeders has led to the development of new yellow and white bean germplasm with high yields, fast cooking times and enhanced iron bioavailability. Moreover, farmers participating in field trials at the University of Zambia selected many of these new fast cooking bean lines as their preferred choice for future production on their own farm. The fast-cooking yellow beans selected by farmers had significantly higher iron bioavailability when compared to local commercial beans and locally produced “biofortified varieties.” This information has the potential to change government policy in Africa because current biofortified varieties are promoted to farmers as being more nutritious, but their iron content and iron bioavailability is much lower than the USDA-ARS developed yellow beans. Several manuscripts detailing these discoveries are currently in preparation.
Domestic Genotype by Environment (G x E) Studies of Fast Cooking Yellow Beans. To investigate the cooking time and iron nutrition of potential yellow beans for commercial production in the United States, several years of evaluation for mineral content and iron bioavailability in a large group of fast and slow cooking yellow beans produced in Michigan (normal soil pH 7) and Nebraska (high soil pH > 8) is now completed. This research was to determine the likelihood of producing high iron bioavailable yellow beans domestically for the use as a specialty market class devoted to addressing the iron needs of vulnerable populations in the United States and aboard. Although iron concentrations of yellow beans are reduced when produced in locations with high soil pH (e.g. Nebraska), several yellow bean lines still delivered high amounts of bioavailable iron. These results show that the high iron bioavailable trait in certain yellow bean market classes (Mayocoba and Manteca) is stable across production environments, unlike iron content, which is very susceptible to soil and growing conditions. This research will provide farmers in the United States and aboard an opportunity to grow yellow beans with enhanced iron nutrition under less-than-ideal growing conditions. A manuscript detailing these findings is currently in preparation.
Yellow By Yellow Recombinant Inbred Line (YYRIL) Mapping Population. Completed measuring the mineral content and iron bioavailability of a Manteca yellow bean (Ervilha) x Green-yellow bean (PI527538) mapping population (400+ RILS over two field seasons) to identify promising molecular markers (QTL) for the high iron bioavailability trait in fast cooking Manteca yellow beans. A QTL located near the j allele on chromosome 10 has been identified as a strong candidate marker for high iron bioavailability in beans after cooking. The j allele is characterized as an important region of the genome that inhibits the production of catechins and condensed tannins in the seed coats of yellow beans. These groups of flavonoids has been previously demonstrated as having strong inhibitor actions on the absorption of iron in the small intestine. A manuscript describing the results of this study is in preparation.
Dietary Fiber Analysis of Fast Cooking Yellow Beans. This project evaluated the relationship between total dietary fiber, cooking time, and iron bioavailability in a large group of yellow beans selected from the USDA’s Yellow Bean Collection (est. 2018). There was a significant relationship between the total dietary fiber (AOAC 2011.25) concentrations and cooking times of yellow beans, which were collected from each of the major yellow bean market classes from bean-consuming regions of the world. In addition, there was a significant relationship between the insoluble dietary fiber concentrations and iron bioavailability of yellow beans, indicating that new breeding targets for insoluble dietary fiber can be implemented to further enhance the iron bioavailability of new bean varieties. These findings support more recent investigations that show fast cooking beans have thinner seed coats and thinner cotyledon cell walls, which are the two main insoluble components of dry beans. A manuscript describing the results of this study is near completion.
Yellow Bean Pasta Development. Bean flour is a highly nutritive, plant-based ingredient with potential for great utility in many food products, including snacks, pasta and baked goods. Manteca yellow beans are a market class of dry beans with a pale-yellow seed coat and many favorable end use quality characteristics, which makes them an ideal flour ingredient for food production. In addition, Manteca yellow beans have more bioavailable iron when compared to other market classes of dry beans, which makes them an ideal target for improved iron nutrition. USDA-ARS has an active Manteca breeding program, adapting them to commercial production with improved seed yield, maturity, harvest quality, cooking time, canning quality and iron bioavailability. However, there is currently no information on the nutritional properties of Manteca beans after being processed into flour. The goal of this research was to evaluate the nutritional attributes of Manteca bean pasta made from advanced breeding lines as compared to commercially available chickpea, wheat and gluten free pastas. The results show that Manteca yellow bean pasta has more than twice the iron content and 3x the iron bioavailability as chickpea, wheat and gluten free pasta. This research demonstrates that the unique iron nutrition of the Manteca yellow bean can be translated into a convenient food product, beating out the other supermarket brands for the delivery of iron, even fortified wheat pasta. This preliminary research has been published in the Bean Improvement Cooperative Annual Report 2023, vol. 66; pages 63-64).
Agronomic Biofortification of Domestic Dry Beans. Foliar application of Fe based fertilizers can potentially increase the Fe content and bioavailability of commercial dry beans produced in the United States. The yield, cooking quality, mineral concentration, and iron bioavailability of two black bean varieties (Black Beard and Zenith) and two navy bean varieties (Merlin and HMS Medalist) are currently being evaluated with and without foliar fertilizer, using multiple on-farm trials located in Michigan. These four varieties were chosen to represent commercial dry beans that growers have adopted based on agronomic traits, as well as commercial standards used for their superior cooking and processing quality. The goal for this research will be to evaluate data on the effectiveness of foliar applications in improving the iron nutrition of Michigan grown black and navy beans from 2-3 years of consecutive field seasons. Preliminary evidence from the first year of experiments suggests that fertilizer treatments consisting of 32 fluid ounces per acre of ‘Max-in Fe®’ applied at two growth stages: Application 1- V2 growth stage and Application 2- R1 growth stage can significantly increase the iron concentrations, as well as the iron bioavailability of black and navy beans. The second year of experiments are currently being conducted this field season (2023) and most likely a third field season will be needed before publication of an official manuscript.
Accomplishments
1. High bioavailable iron yellow beans for domestic production and abroad. The common bean has been targeted as a staple food crop to enhance Fe nutrition both domestically and abroad. ARS scientists at Ithaca, New York, and East Lansing, Michigan, have developed two fast-cooking, high bioavailable iron, and high yielding yellow bean varieties. As of May 2023, these yellow bean varieties were under review for an official germplasm or varietal release in the U.S. These same yellow beans have also been well received and are highly desired by producers in Uganda and Zambia as they outperform local commercial varieties in on-farm trials. Overall, this research demonstrates that these yellow bean varieties possess the unique combination of fast-cooking, high yielding, and high bioavailable iron traits; thus, showing strong potential to deliver significantly more absorbable iron relative to other beans in the food system.
2. Improved Flavonoid Quantification. Quantification of flavonoids in food is a challenging technical task, requiring expensive instrumentation and highly skilled scientists. ARS scientists at Cornell University, Ithaca, New York, have firmly established capability to quantify approximately 28 of the major flavonoids in foods, most notably the major flavonoids that are found in seed coats of the common bean. In developing this capability, Ithaca scientists also developed a novel extraction protocol demonstrating that previous studies on flavonoid quantification were significantly underestimating many compounds. This enhanced methodology has potential to generate more accurate quantification of flavonoids in beans and for other foods. More accurate flavonoid measurement is also critical to properly guiding bean breeding programs as the flavonoid related color of the bean seed coat is a major factor in consumer preference. From a nutritional standpoint, this capability is extremely important as flavonoids have profound effect on iron absorption, and are related to antioxidant benefits, anti-obesogenic benefits, and anti-diabetic benefits.
Review Publications
Wiesinger, J.A., Marsolais, F., Glahn, R.P. 2022. Health implications and nutrient bioavailability of bioactive compounds. In: Siddiqu, M. and Uebersax, M. Dry Beans and Pulses Production, Processing and Nutrition. 2nd edition. Hoboken, NJ: John Wiley & Sons Ltd. p. 505-530.
Mclean, P.E., Lee, R., Howe, K.J., Osborne, C., Grimwood, J., Levy, S., Haugrud, A.P., Plott, C., Robinson, M., Skiba, R.M., Tanha, T., Zamani, M., Thannhauser, T.W., Glahn, R.P., Schmutz, J., Osorno, J., Miklas, P.N. 2022. The common bean V gene encodes flavonoid 3'5' hydroxylase: A major mutational target for flavonoid diversity in angiosperms. Frontiers in Plant Science. 13:869582. https://doi.org/10.3389/fpls.2022.869582.
