Frontiers in Agricultural Sustainability: Studying the Protein Supply Chain to Improve Dietary Quality

Resources

Keynote address

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The science of food proteins

He L, Yang H, Hou Y, et al. Effects of dietary L-lysine intake on the intestinal mucosa and expression of CAT genes in weaned piglets. Amino Acids. 2013;45(2):383-91.

Kim J, Song G, Wu G, et al. Arginine, leucine, and glutamine stimulate proliferation of porcine trophectoderm cells through the MTOR-RPS6K-RPS6-EIF4EBP1 signal transduction pathway. Biol Reprod. 2013;88(5):113.

Laparra JM, Glahn RP, Miller DD. Bioaccessibility of phenols in common beans ( Phaseolus vulgaris L.) and iron (Fe) availability to Caco-2 cells. J Agric Food Chem. 2008;56(22):10999-1005.

Merritt EK, Stec MJ, Thalacker-Mercer A, et al. Heightened muscle inflammation susceptibility may impair regenerative capacity in aging humans. J Appl Physiol (1985). 2013;115(6):937-48.

Newgard CB, An J, Bain JR, et al. A branched-chain amino acid-related metabolic signature that differentiates obese and lean humans and contributes to insulin resistance. Cell Metab. 2009;9(4):311-26.

Rezaei R, Wang W, Wu Z, et al. Biochemical and physiological bases for utilization of dietary amino acids by young pigs. J Anim Sci Biotechnol. 2013;4(1):7.

Tako E, Laparra MJ, Glahn RP, et al. Biofortified black beans in a maize and bean diet provide more bioavailable iron to piglets than standard black beans. J Nutr. 2009;139:305-9.

Tan SY, Yeung CK, Tako E, et al. Iron bioavailability to piglets from red and white common beans (Phaseolus vulgaris). J Agric Food Chem. 2008;56(13):5008-14.

Thalacker-Mercer A, Stec M, Cui X, et al. Cluster analysis reveals differential transcript profiles associated with resistance training-induced human skeletal muscle hypertrophy. Physiol Genomics. 2013;45(12):499-507.

Thalacker-Mercer AE, Ingram KH, Guo F, et al. BMI, RQ, diabetes, and gender affect the relationships between amino acids and clamp measures of insulin action in humans. Diabetes. 2014;63(2):791-800.

Thalacker-Mercer AE, Fleet JC, Craig BA, et al. The skeletal muscle transcript profile reflects accommodative responses to inadequate protein intake in younger and older males. J Nutr Biochem. 2010;21(11):1076-82.

Wu G. Functional amino acids in nutrition and health. Amino Acids. 2013;45(3):407-11. PMID

Sustainability challenges and bottlenecks

Arimond M, Ruel MT. Dietary diversity is associated with child nutritional status: evidence from 11 demographic and health surveys. J Nutr. 2004;134(10):2579-85.

DeClerck FA, Fanzo J, Palm C, Remans R. Ecological approaches to human nutrition. Food Nutr Bull. 2011;32(1 Suppl):S41-50.

Fanzo JC, Pronyk PM. A review of global progress toward the Millennium Development Goal 1 Hunger Target. Food Nutr Bull. 2011;32(2):144-58.

Guzman JA, Moriasi, DN, Starks, PJ, et al. Mapping and spatiotemporal analysis tool for hydrological data: Spellmap. Environmental Modelling & Software. 2013;48:163-70.

Kumar P, Coronel P, Simunovic J, Sandeep KP. Feasibility of aseptic processing of a low-acid multiphase food product (salsa con queso) using a continuous flow microwave system. J Food Sci. 2007;72(3):E121-4.

Kumar P, Reinitz HW, Simunovic J, et al. Overview of RFID technology and its applications in the food industry. J Food Sci. 2009;74(8):R101-6.

Moriasi DN, Gowda P, Arnold JG, et al. Modeling the impact of nitrogen fertilizer application and tile drain configuration on nitrate leaching using SWAT. Agricultural Water Management. 2013;130:36-43.

Remans R, Flynn DF, DeClerck F, et al. Assessing nutritional diversity of cropping systems in African villages. PLoS One. 2011;6(6):e21235.

Steed LE, Truong VD, Simunovic J, et al. Continuous flow microwave-assisted processing and aseptic packaging of purple-fleshed sweetpotato purees. J Food Sci. 2008;73(9):E455-62.

Termote C, Bwama Meyi M, Dhed'a Djailo B, et al. A biodiverse rich environment does not contribute to a better diet: a case study from DR Congo. PLoS One. 2012;7(1):e30533.

Programs and approaches to solve sustainability challenges

Dubé L, Pingali P, Webb P. Paths of convergence for agriculture, health, and wealth. Proc Natl Acad Sci U S A. 2012;109(31):12294-301.

Pingali PL. Green revolution: impacts, limits, and the path ahead. Proc Natl Acad Sci U S A. 2012;109(31):12302-8.

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Innovations in protein production

Forgacs G. Tissue engineering: Perfusable vascular networks. Nat Mater. 2012;11(9):746-7.

Hughes GJ, Ryan DJ, Mukherjea R, Schasteen CS. Protein digestibility-corrected amino acid scores (PDCAAS) for soy protein isolates and concentrate: criteria for evaluation. J Agric Food Chem. 2011;59(23):12707-12.

Jakab K, Norotte C, Marga F, et al. Tissue engineering by self-assembly and bio-printing of living cells. Biofabrication. 2010;2(2):022001.

Owens CM, Marga F, Forgacs G, Heesch CM. Biofabrication and testing of a fully cellular nerve graft. Biofabrication. 2013;5(4):045007.

Post MJ. Cultured beef: medical technology to produce food. J Sci Food Agric. 2013. [Epub ahead of print]

Post MJ. Cultured meat from stem cells: challenges and prospects. Meat Sci. 2012;92(3):297-301.

Post MJ, Rahimi N, Caolo V. Update on vascularization in tissue engineering. Regen Med. 2013;8(6):759-70.

van der Schaft DW, van Spreeuwel AC, Boonen KJ, et al. Engineering skeletal muscle tissues from murine myoblast progenitor cells and application of electrical stimulation. J Vis Exp. 2013;(73):e4267.

Schasteen CS, Wu J, Schulz MG, Parsons CM. Correlation of an immobilized digestive enzyme assay with poultry true amino acid digestibility for soybean meal. Poult Sci. 2007;86(2):343-8.

Sun W, Forgacs G. The 2010 International Conference on Biofabrication (BF2010) special issue. Biofabrication. 2011;3(3):030201.

Sponsors

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The Food and Agriculture Organization (FAO) recently estimated that more than 800 million people, nearly a seventh of the world's population, are chronically hungry. This number could increase: a UN report released in June 2013 projected that the world population will reach 8 billion by 2025 and 11 billion by 2100, emphasizing the urgent need to find sustainable solutions to food insecurity.

The Frontiers in Agricultural Sustainability conference featured discussion on the science of food proteins, challenges and bottlenecks in achieving a sustainable protein supply, new technologies for protein production, and nutrition interventions implemented at the level of the farm, community, and country.

Hunger and micronutrient malnutrition are distinct nutritional problems. Hunger is a problem of food quantity, while micronutrient malnutrition is a problem of food quality. In her keynote address, Barbara Burlingame explained that food quality has often been misguidedly targeted through clinical and pharmaceutical solutions such as individual nutrient supplements, fortifications, and ready-to-use therapeutic formulations.

Burlingame argued that to improve food quality we should instead focus on dietary diversity, whole foods (as opposed to individual micronutrients) containing a spectrum of nutrients and beneficial bioactive non-nutrients, and sustainable farming systems. Human health is inseparable from the health of ecosystems: rich local food sources reduce the risk of malnutrition. Thus, dietary interventions should complement local biodiversity—the variety of livestock, crops, forestry, and fish available within an ecosystem—to provide sustainable solutions to malnutrition. She presented data to support a whole-foods approach to nutrition and described policy initiatives linking efforts by agricultural, health, and environmental sectors to build better food systems.

Dennis Miller is also interested in micronutrient malnutrition, particularly in populations that rely heavily on plant-based foods. He agreed with Burlingame's emphasis on dietary diversity but argued for the use of micronutrient fortification. He pointed to data in livestock showing that bio-fortified food crops can overcome micronutrient deficiency and improve animal health.

Grain legumes such as beans and lentils, which are protein-rich staple foods, are the focus of USAID's Feed the Future initiative, which aims to improve nutrition for children and women of childbearing age. Irvin Widders described strategies to increase grain legume productivity and improve knowledge of the nutritional value of legumes among undernourished rural populations in Guatemala.

The importance of biodiversity for dietary quality is widely accepted, but there is debate about how to use this knowledge in agriculture to improve nutrition and health. Jessica Fanzo reviewed the literature to identify how to improve nutritional security and to find knowledge gaps.

Dietary protein intake is known to decrease with age. Aging bodies cope with this decrease by breaking down protein in muscle for energy. Together with changes in muscle protein metabolism, this process leads to sarcopenia (age-related skeletal muscle atrophy) and metabolic dysfunction, which can lead to diseases such as diabetes. Anna Thalacker-Mercer presented data on the effect of dietary intake on muscle metabolism, based on transcriptomic and metabolomic studies.

Animal meat has a higher protein content than plant sources, and global meat production is expected to double by 2050. However, the supply of plant-based foods, upon which both humans and animals rely, is expected to remain stable over this time. Guoyao Wu described his efforts to increase animal growth and reproduction despite plant food scarcity by improving protein production in farm animals. Josip Simunovic described his efforts, at other end of the animal protein supply chain, to develop aseptic processing technologies to improve the safety, shelf life, and nutritional profile of processed meats.

Another way to improve animal productivity—the contribution of animal protein to the food supply—is to improve animal productivity systems. In the case of beef cattle this goal is achieved by improving forage, using a mixture of cropland, prairies, and native grasslands. Jean Steiner described long-term research projects intended to reduce the environmental footprint of grazing and agronomic activity and to increase the resilience of beef cattle to variability in climate, market, and government policy.

With an endowment from the Tata Education and Development Trust, Prabhu Pingali is deploying several interventions in India, focused on child malnutrition, food, clean water and sanitation, and poverty. He described three interventions intended to improve household nutrition in rural India.

At the end of the conference, a panel discussed new methods for producing protein, including reclaiming protein material from previously wasted production streams, optimizing single-celled photosynthetic organisms to produce consumable nutrients, manufacturing protein in the lab through bioprinting, and engineering stem cell-derived tissue. These efforts aim to create sustainable alternatives to animal protein in response to a scarcity of natural resources required for its production.

Keynote Speaker:
Barbara Burlingame, Food and Agriculture Organization of the United Nations

Highlights

• Fortifications, supplements, and therapeutic injections of individual micronutrients are inadequate approaches to malnutrition and cannot replace whole complex foods, according to Barbara Burlingame of the FAO.
• Biodiversity is essential to the nutritional quality of a sustainable diet, and preventing its erosion should be a priority.

The role of agriculture in diet: quantity versus quality

UN Secretary-General Ban Ki-moon's Zero Hunger Challenge, announced in 2013, presents his vision for global food security: 100% access to adequate food throughout the year, 100% growth in smallholder productivity and income, 0% stunted children under age 2, and 0% food loss or waste. These goals are arrayed around a central aim: sustainable food systems. Keynote speaker Barbara Burlingame, deputy director of the Food and Agriculture Organization's Nutrition Division, elaborated on this goal; in her vision, sustainable agriculture would be guaranteed by eliminating unnecessary monoculture, intensive livestock industries, overuse of agricultural chemicals, and food-chain inefficiencies.

Micronutrient deficiency, which is pervasive in much of the developing world, has long been targeted through medical interventions such as ready-to-use therapeutic supplements. But the problem persists because these medical approaches are not sustainable. (Image courtesy of Barbara Burlingame)

Burlingame argued that fortifications, supplements, and therapeutic injections of individual micronutrients are inadequate approaches to micronutrient malnutrition because they do not mimic the complexity of food, which is comprised of nutrients and beneficial bioactive non-nutrients. The FAO recently developed a code of conduct for the food industry that emphasizes the inseparable relationship between human health and ecosystem health and promotes the idea that a diet based on whole foods, not individual micronutrient supplementation, provides ideal nutrition.

The code of conduct developed by the FAO and its collaborators as a guide for the food industry emphasizes the idea that sustainable diets are comprised of complete foods, not micronutrient supplementation. (Image courtesy of Barbara Burlingame)

Biodiversity has often been ignored in the study of nutrient content. The sole cultivation of plant species with a high content of specific nutrients has caused a tremendous erosion of biodiversity. For example, areas of Asia in which thousands of rice varieties were once grown now use more than 70% of cultivable land to grow three varieties carrying high levels of iron or zinc, resulting in a loss of genetic diversity and nutrient complexity. The recognition of varietal differences in nutrient content prompted the Internal Rice Commission to recommend in 2013 that rice biodiversity and nutritional composition be analyzed before engaging in genetic modification.

Burlingame recommended that policy makers look to local food systems and ecosystems when implementing programs for malnutrition, rather than to global, non-contextual recommendations. This approach would help to prevent well-intentioned aid programs, which often apply a one-size-fits-all solution without characterizing local agro-ecological zones, from unwittingly implementing policies that damage local diets and ecosystems.

Burlingame concluded by discussing notable recommendations made in 2013 by the Commission on Genetic Resources for Food and Agriculture to the FAO. These recommendations are intended to promote collaboration among government sectors focused on biodiversity and environment and academic departments and nonprofits focused on human nutrition. She pointed out that African nutrition experts have long argued that agrobiodiversity determines dietary quality, and is therefore central to food security, but this idea is only now finding broader acceptance.

Speakers:
Anna Thalacker-Mercer, Cornell University
Guoyao Wu, Texas A&M University
Dennis Miller, Cornell University

Highlights

• Reduced dietary protein intake causes muscle loss in the elderly due to changes in the expression of genes involved in protein catabolism. Branched-chain amino acids and glycine play a role in the body's response to insulin.
• The concept of the "ideal protein" should be revised to include non-essential amino acids along with essential amino acids, because both are required for livestock reproduction and protein production.
• Micronutrient biofortification is a valid way to enhance dietary protein quality in regions where people suffer from malnutrition, according to Dennis Miller of Cornell University.

The role of proteins in aging and metabolic dysfunction

When dietary protein intake is reduced, as it is in the elderly, the body breaks down skeletal muscle protein to generate the amino acids it needs for energy. Muscle also becomes less able to take up and use protein, leading to muscle atrophy. Anna Thalacker-Mercer of Cornell University has identified a crucial clue to the impact of aging on muscle metabolism from her studies of skeletal muscle transciptome (gene expression) profiles. At protein intakes below the recommended dietary allowance (RDA) (represented as LPro in the figure below), the expression of genes involved in protein synthesis appears similar in young and old men. However, when protein intake increases in young men the gene profile suggests an increase in protein synthesis, which does not appear in older men. When the older men consume a low-protein diet, the gene profile suggests heightened protein catabolism compared to the young.

The gene expression profile shows that habitual consumption of protein diets at or below the recommendation by old men does not increase expression of protein synthesis genes but does increase expression of protein catabolism genes. (Image courtesy of Anna Thalacker-Mercer)

Branched-chain amino acids such as leucine have recently been implicated in metabolic dysfunction. They are found at higher levels in the blood in obese and insulin-resistant individuals compared to healthy adults. Using metabolomic approaches, Thalacker-Mercer identified a strong correlation between another amino acid, glycine, and insulin action: healthy adults had higher circulating levels of glycine than obese adults and those with type 2 diabetes, suggesting this amino acid is protective against insulin resistance.

She also found that the relationship between amino acids in circulation and insulin action is affected by the availability or the use of fat instead of carbohydrates as a fuel source, suggesting that skeletal muscle atrophy might be compounded by obesity. Her team is now investigating whether glycine could be useful as a dietary supplement in elderly adults and whether amino acids are biomarkers of metabolic dysfunction or play a causal role in its development.

Improving the efficiency of animal protein production

One way to increase the global animal protein supply is to increase the efficiency with which dietary protein consumed by farm animals is converted into tissue or milk proteins. Animals utilize dietary protein through a proteolytic pathway that sequentially hydrolyzes protein macromolecules into small peptides and amino acids that are used to synthesize high-quality proteins.

Protein consumed in the diet undergoes proteolytic degradation in the stomach and small intestine to produce free amino acids that are used to synthesize high-quality protein for tissue production. (Image courtesy of Guoyao Wu)

However, the efficiency with which animals produce protein is low. Some of the amino acid content of dietary protein is lost through protein degradation in the intestinal mucosa (instead of in the gut, where amino acids can be reabsorbed). In livestock, amino acid catabolism by intestinal bacteria is high, protein synthesis in skeletal muscle is low, and non-essential amino acids (NEAA) are not included in dietary protein.

Guoyao Wu of Texas A&M University has shown in swine that NEAA synthesis from an EAA-only diet is inadequate for maximal growth of just-weaned animals: over 90% of newly synthesized NEAAs are degraded in the animals' small intestines and are not taken up for protein synthesis in tissue. Wu has formulated an "optimal" protein diet that contains adequate proportions and amounts of all amino acids, which has helped lactating sows to increase milk production by 17%–26%. Wu therefore proposed modifying the long-standing "ideal protein" concept, which ignored NEAAs in the diet, to now include these amino acids in animal dietary protein, arguing that this change would improve the efficiency of livestock feed.

The mTOR pathway is a key cell signaling pathway in protein synthesis. It is activated by amino acids such as arginine in skeletal muscle and lactating tissue. Wu has found that dietary arginine supplementation in breeding sows can increase litter birth rates by 20% and double the size of litters. In his view, improvements in farm animal productivity are essential to produce high-quality animal protein to satisfy growing demand and offset resource scarcity.

Micronutrient-fortified plant-based proteins as a nutrition source

Most people depend on cereal grains for more than half of their caloric intake. But cereal grains have a low concentration of vital amino acids and are "incomplete" because they do not contain every amino acid. Dennis Miller of Cornell University described how to overcome these shortfalls in protein quality. Each protein source has a different composition of amino acids. Protein complementarity, practiced for centuries, combines proteins from different sources—whole wheat and beef, for instance—to yield a higher quality protein source than can be obtained from either food individually. Protein quality can also be enhanced through plant breeding, which uses genetic diversity to selectively cultivate variants with desired traits.

Micronutrient biofortification has been used with repeated success, first in the production of iodized salt in the 1920s and later in the production of folic acid-enriched foods in the 1990s. Miller described his own work, undertaken with HarvestPlus, a global alliance of research institutions that develops staple food crops to enhance mineral and vitamin content.

One project aimed to determine whether iron in a newly developed biofortified variant of the common bean is bioavailable for hemoglobin synthesis. After 5 weeks, pigs fed the high-iron bean had a significantly increased total body hemoglobin iron content over those fed the standard bean, suggesting that biofortified beans could increase the intake of bioavailable iron in human populations that consume beans as a dietary staple. While acknowledging that micronutrient biofortification might not be a silver bullet, Miller argued for its validity as an approach to improve nutrition.

Consumption of black beans with high iron content (106ug/g) significantly increased the amount of bioavailable iron found in hemoglobin in pigs after 5 weeks, as compared with consumption of black beans with standard iron content (71ug/g). (Image courtesy of Dennis Miller)

Speakers:
Jean Steiner, U.S. Department of Agriculture
Jessica Fanzo, Columbia University
Josip Simunovic, North Carolina State University

Highlights

• Improving the sustainability of forage-based animal productivity systems and reducing their environmental footprint can increase resilience to vagaries of climate, market, and government policy.
• Biodiversity has a huge impact on nutritional quality and health outcomes, especially in rural communities.
• An aseptic processing and sterilizing technique that processes muscle foods under flow conditions rapidly and volumetrically (as opposed to sterilizing canned food) without compromising taste and nutritional value will improve animal protein availability and consumption.

Building a robust cattle production system to withstand climate, resource, and market variability

The beef cattle production system in most parts of the world, including in the Southern Great Plains of the U.S., depends on crop, pasture, and native grasslands for forage. The system is increasingly vulnerable to variability in climate, dynamic markets, and changing agricultural, energy, and environmental policies. Jean Steiner of the U.S. Department of Agriculture gave an overview of a series of research projects undertaken by a multi-institutional collaboration to strengthen the resilience of the beef cattle production system.

Steiner explained that a major goal of this project is to reduce the environmental footprint of beef-grazing systems by reducing the emissions of potent greenhouse gases such as nitrous oxide (N₂O) and methane. N₂O is increased by the application of nitrogen fertilizer to crops on forage land. Steiner is building a database to improve our knowledge of how to manage agroecosystem fertilization and reduce N₂O emissions. Her team is analyzing fertilizer management practices to find ways to minimize losses through N₂O emissions (rate, timing, and type of fertilization) and collecting information about background emissions from unfertilized prairie land.

Methane emissions from cattle depend on the quality of forage (including the types of species consumed) and the type of livestock (cow, calf, heifer, etc.). The team is using grazing lands as open laboratories, tagging cattle with GPS collars to identify their grazing patterns and preferences to develop emissions-reducing steps in the production cycle. Efforts are also underway to improve the quality of vegetation, increase soil carbon sequestration, and understand how agronomic management strategies impact water quantity and quality, which is particularly important in regions prone to drought.

One project aims to recruit citizen scientists to participate in information gathering. An iPhone app assimilates GPS-tagged field photos to provide information on changes in farming conditions. (Image presented by Jean Steiner courtesy of Xiangming Xiao, University of Oklahoma)

Evidence linking biodiversity and nutritional quality

Biodiversity describes genetic diversity within and between species and the relationships between species and their ecosystems. The evidence connecting biodiversity to improved dietary quality is still being compiled. Jessica Fanzo of Columbia University reviewed published data describing a role for biodiversity in nutrition and health. She began with a study associating improved dietary diversity (defined by the number of different foods consumed over a reference period) with a reduction in stunting in children, which is one measure of a nutritional outcome.

According to Fanzo, more studies are now documenting the nutritional composition of local species, including the studies led by keynote speaker Barbara Burlingame. These compositional studies indicate that species diversity does not always translate into dietary diversity and quality. Although many different grain crops are grown in West Africa, for example, local nutritional content is mostly limited to carbohydrates and a few micronutrients, and most of the crops grown have the same nutritional composition.

Local biodiversity is particularly important for nutritional quality in rural communities, according to one meta-analysis that only examined populations living in highly biodiverse areas. But according to another study, many such communities do not capitalize on their knowledge of wild foods. Fanzo explained that using such knowledge can improve nutritional security: another study found that the addition or removal of individual wild foods can result in starkly different nutritional outcomes (compositions in daily diet) in rural areas.

Fanzo also discussed the politics and cost burden of biodiversity. She argued that biodiversity should be conserved, but its "custodians" (the farmers) must be protected from poverty and loss of local nutritional quality. The latter often occurs when indigenous foods enter the mainstream and are marked for export rather than for local consumption.

The Millenium Ecosystems Assessment group has identified several drivers and challenges that affect biodiversity, ecosystem services, and human health. (Image courtesy of Jessica Fanzo)

Improving technologies for industrial muscle-food preservation

One challenge faced by the industry that processes so-called muscle foods—hot dogs, salami, hams—is the limited shelf life and potential for spoilage during distribution and storage of raw frozen and thermally processed "fully cooked" meats. Canned and sterilized muscle foods are shelf-stable at ambient temperatures, but are rapidly losing market share because of their low sensory quality: they "smell and taste bad," as Josip Simunovic of North Carolina State University put it.

The sterilization process for canned solid food—that is, the requirement to deliver lethal over-cooking at temperatures that can kill pathogens such as Salmonella and Escherichia coli—results in over-processing of everything surrounding the so-called cold spot at the center of the canned product. Overcooking results in loss of sensory quality, destroys valuable nutrients, wastes energy, and limits the maximum package size (products in large cans are the most damaged).

Simunovic has developed a new aseptic processing technique to more rapidly and uniformly heat meat products. In contrast to canning, in which products are sterilized within the package, his method sterilizes food products under continuous flow (as a continuously flowing liquid substance as opposed to a solid lump), and then combines rapidly cooled products with separately sterilized packaging under aseptic conditions. The thermal technology used for sterilization is a focused microwave energy that creates uniform heat distribution under flow. This technology has been refined in the last decade and can be used on large, industrial volumes and non-homogeneous products involving different textures and consistencies.

Aseptic food processing offers the advantage of producing a very high volume of high-quality products by sterilizing products under flow conditions (in liquid form) as opposed to sterilizing a pre-packaged can. (Image courtesy of Josip Simunovic)

Speakers:
Prabhu Pingali, Cornell University
Irvin Widders, Michigan State University

Highlights

• Chronic malnutrition in India could be alleviated by increasing household access to food by improving income, increasing the food supply, and changing behavior and food distribution.
• Dietary protein quality has been improved in rural Guatemala by encouraging consumption of legume varieties developed to increase crop yield. Quality seeds and information about crop management strategies are distributed with the help of local, trusted government entities.

Overcoming India's malnutrition problem

Despite its recent economic boom and thriving, burgeoning middle class, India still faces high rates of poverty, hunger, and malnutrition. Prabhu Pingali of Cornell University argued, however, that an opportunity exists for an agricultural renaissance, based on government investment in rural agricultural infrastructure, innovations in genomics and biofortification, ease of information dissemination through cellular technologies, increased enrollment in safety net programs, and growth of women's organizations in rural communities.

Pingali has assembled a framework that draws together research by his group and others on household access to food and food-sharing practices. Interventions are focused on improving household and individual nutrition; for example, one project works to convince heads of household to change food allotment practices. Based on his observations in rural India, Pingali is focused on improving the nutrition and health of women of childbearing age and on reducing stunting and malnutrition in children under 2 years old.

The Tata-Cornell Agricultural and Nutrition Initiative aims to improve nutrition in India by implementing a framework of ideas to address household food access and individual nutrition. (Image courtesy of Prabhu Pingali)

The project, which began in fall 2013, operates in three sites, with each serving as a test for a different intervention. The goal at the first site is to promote household income and increase the local supply of food and micronutrients through social programs. The researchers are looking for ways to improve local labor dynamics, market opportunities, and other aspects of farming productivity. At the second site, researchers are trying to improve access to clean water and sanitation by, for example, helping to develop village-level water purification plants. A major reason for child malnutrition in rural areas, especially of female children, is inequitable distribution of food within families, with boys and men fed before women and girls. At the third site, researchers are therefore attempting to drive positive behavioral change and empower women by working through local women's organizations.

Improving the nutritional quality of diets through grain legumes

Grain legumes such as beans, lentils, and chickpeas are multifunctional staple crops that are "nutrient dense," with high protein content, complex carbohydrates, iron, zinc, vitamin B, and other micronutrients. These are among the most affordable crops for nutritional value and are viewed as "women's crops" for their sustenance of women's livelihoods in many parts of the world.

The productivity of these crops in many areas in the developing world is pitifully low, however. Irvin Widders of Michigan State University is working at the Legume Innovation Lab to close the yield gap—the difference between the genetic yield potential and the actual yield on farms. The team looks at many aspects of crop yield, from molecular genetics to crop management strategies that aim to improve nutrition quality and marketing approaches.

The Legume Innovation Lab aims to increase grain legume productivity in low-income farming communities. In Guatemala, food insecurity is high and more than half of children are chronically malnourished. (Image courtesy of Irvin Widders)

Through USAID's Feed the Future program, Widders is working to reduce undernutrition in Guatemala, where 80% of children in rural areas are stunted and a majority of the population lives in poverty. Collaborating with the country's Ministries of Agriculture and Health, Widders aims to increase bean production on farms and consumption of beans by children and women of childbearing age. Interventions aim to improve access to quality seeds of bean varieties with enhanced yield potential; to improve integrated crop management practices, such as crop rotation; to implement simple steps, such as disseminating sacks for long-term, non-wasteful storage; to promote seed exchanges; and to improve local understanding and appreciation of beans as a nutritious, ancestral crop.

Another project is looking at the impact on child health of regular consumption of pulses by examining gut microbial flora, intestinal nutrient absorption, and immune function. It also examines whether the benefits of pulse consumption extend to better child growth and reduced incidence of diarrheal disease.

Chair:
Michael Morrissey, Oregon State University
 
Panelists:
Gabor Forgacs, University of Missouri–Columbia
Geoffrey von Maltzahn, Flagship Ventures
Mark Post, Maastricht University, Netherlands
Charles Schasteen, DuPont Nutrition & Health Protein Solutions

Highlights

• Improved knowledge of raw soy whey components and better separation technology has allowed much previously wasted process material to be reclaimed to create useful and healthy soy protein products.
• New technologies, combined with genome, proteome, and microbiome research, are catalyzing start-up companies focused on global problems in nutrition and health.
• Beef produced in the lab from stem cells via regenerative techniques could provide an alternative to current non-sustainable protein production practices.

Reclaiming healthy, sustainable products from soy protein waste streams

The end of the conference featured a panel chaired by Michael Morrissey of Oregon State University. The panelists discussed new methods for producing protein, which are intended to create sustainable alternatives to animal protein in response to a scarcity of natural resources required for its production. Soy protein, the most energy efficient and accessible form of plant-based high-quality protein, will play an important role in regions with huge projected population growth and limited infrastructure to produce animal protein. When soybeans are processed to create protein ingredients, the starting material used by the food industry in commercial products is a form known as defatted soy flake. The isolated soy protein production process is wasteful, however, and produces products from only 46% of the starting soy flake

Charles Schasteen of DuPont Nutrition & Health Protein Solutions has formulated a process to mitigate this waste. The feed material, raw soy whey, is 2% solids and 98% water. The process concentrates and separates this starting material into individual components, such as soy whey protein, soy whey sugars, soy whey minerals, and water, each of which is usable at the end of the process. Soy whey protein has several traits—unprecedented solubility across a range of pH, low viscosity, and high emulsification—that make it a viable replacement for dairy proteins. Soy whey protein forms a more stable foam than egg white, for example, and is a healthier alternative to chemical-based emulsifiers. These new protein products for use as food ingredients and in beauty and personal care products are targeted for prototype availability later in 2014.

Soy whey protein isolated from raw soy whey has physicochemical properties that allow for multiple applications in the food industry, including as a replacement for eggs in mayonnaise. (Image courtesy of Charles Schasteen)

Launching companies for innovation across the nutrient supply chain

Geoffrey von Maltzahn of Flagship Ventures presented innovative ideas and technologies that have driven the launch of companies focused on nutrition and health. In his view, agriculture practiced in its current form is a wasteful endeavor, using over 40% and 75%, respectively, of arable land and fresh water while producing over 30% of greenhouse gas emissions, degrading land, depleting ground water, and leading to habitat destruction and loss of biodiversity.

A start-up called Essentient aims to streamline food production by eliminating the need for arable land and wasteful intermediary steps in cultivation, harvesting, storage, and transportation, turning instead to single-celled photosynthetic organisms engineered to produce and secrete nutrients currently derived from agriculture at "supra-agricultural efficiencies." Early-stage nutrient factories, whose yield has far outstripped that of traditional agriculture, are being pilot-tested in non-arable regions.

Nutriculture: Single-cell organisms have been genetically optimized to convert purified nutrient streams of sunlight, carbon dioxide, water, and nitrogen into the nutrients currently derived from agriculture at "supra-agricultural" levels. (Image courtesy of Geoffrey von Maltzahn)

Another company, Pronutria, has built a proprietary library of more than a billion protein polymers (amino acid chains) found in the typical Western diet. By comparing known clinically proven amino acid combinations to the library, the company has designed proteins with desired characteristics to treat disease. These proteins can be delivered as prodrugs, which are digested to release a specific combination of amino acids. Some protein candidates are in clinical trials to treat muscle loss. Other candidates are scheduled to begin trials in 2014 for metabolic disease.

Von Maltzahn also described efforts to pioneer a new type of medical treatment involving the human microbiome at a start-up called Seres Health. The company designs "Ecobiotics" to therapeutically adjust microbial ecology for medical benefit. Another start-up, Symbiota, is exploiting knowledge of plant microbiota to improve crop yield, pathogen resistance, and stress resilience.

Stem cell hamburgers and bioprinted steak: lab-made animal protein to replace livestock meat

Conventional beef production is unsustainable. Beef cattle have a poor bioconversion rate—about 15%—from feed or grass input to edible protein output and are a huge environmental burden. Nonetheless, meat production falls short of demand. Mark Post of Maastricht University, a pioneer in stem cell technology tissue engineering, and Gabor Forgacs of University of Missouri–Columbia made the case for lab-derived meat products as an alternative to livestock meat.

To produce meat in the lab, muscle tissue derived from a cow via needle biopsy is used to extract satellite cells—stem cells with proliferative capacity that differentiate into skeletal muscle. A single stem cell can yield up to 10¹⁴ cells, which could replace up to 10⁴ kg of conventional meat. A few hundred cells can self-organize into myotubes, which when added to a collagen gel supplemented with basement membrane, organize between two anchor points to form an early form of skeletal muscle tissue. The tension between the two points enhances protein synthesis and maturation. Individual muscle strips grown in this way form the basis of processed meat, and a proof-of-concept hamburger was unveiled in 2013.

Stem cells extracted from cow muscle tissue that self-organize into muscle strips on a bed of collagen and undergo maturation have served as the basis for a lab-grown hamburger. One hamburger requires 60 x 10 ⁹ satellite cells. Eventually, researchers hope to grow cells in a 25 000 liter incubator with the capacity to provide 40 000 people with a year's supply of meat. (Image courtesy of Mark Post)

Post is improving the efficiency of the process by eliminating the need for culture media and adjusting the biochemical and mechanical structure of the tissue scaffold to enhance tissue viability. His team is also working to make cultured beef that more closely mimics its natural counterpart in taste and composition.

Post's cultured meat can only be used in ground meat products because it is assembled from individually cultured muscle fibers. To produce meat that reflects the geometry and composition of tissue, Forgacs is using bioprinting technology, which lays down bio-ink units—a preparation of multicellular aggregates—with support materials along an architectural template. Structural formation, or "magic" as he put it, happens post-printing, in a process similar to embryonic development in vivo. When the bioprinted material has reached the desired thickness and shape, cells assemble, fuse, and undergo morphogenetic changes resulting in tissue that largely resembles animal meat. Several challenges remain, most notably scaling up the process, reducing cost, and achieving consumer acceptance.

Another method for producing meat in the lab involves bioprinting multicellular aggregates that undergo post-printing changes to form structures resembling animal meat. (Image courtesy of Gabor Forgacs)

Like the other speakers at the symposium, who are all in pursuit of sustainable sources of protein, Forgacs and Post are keen to overcome these challenges. They believe that the combination of dwindling natural resources and global population growth suggests that alternative protein sources, such as those derived from the lab, might be not a choice but a necessity in the future.