Amaranth proteins: as novel macromolecules for food systems

9 - World Distribution in Relation to Economic Losses

This review is dedicated to exploring recent advancements in the study of amaranth grain and presents research primarily on Amaranthus species such as Amaranthus cruentus, Amaranthus hypochondriacus, and Amaranthus caudatus, and to a lesser extent Amaranthus hybridus, Amaranthus mantegazzianus, Amaranthus muricatus, Amaranthus tuberculatus, Amaranthus viridis, Amaranthus spinosus, and Amaranthus tenuifoliu. Amaranth (Amaranthus spp.) is a promising, high-yield pseudocereal crop with significant commercial potential for developing functional food products. It contains a wide range of bioactive compounds, including squalene, tocopherols, phenolic compounds, phytates, and vitamins, which possess important physiological properties. Amaranth grain is characterized by high levels of starch, proteins, minerals, and dietary fiber. Moreover, amaranth proteins are distinguished by a balanced amino acid composition and exhibit greater resistance to external factors compared to animal-derived proteins. Grains of amaranth are free of gliadin, making it a valuable nutritional source for individuals with celiac disease, an immune-mediated disorder. Unlike traditional cereals, where prolamins and glutelins dominate the protein composition, the proteins of pseudocereals like amaranth primarily consist of albumins and globulins. The processing methods of amaranth grain influence their quantitative and qualitative composition, often significantly improving their physicochemical, antioxidant, functional, and rheological properties. This work provides a detailed analysis of amaranth's chemical composition and bioactive components, along with its evaluation of therapeutic and preventive properties. Amaranth protein fractions (albumin, globulin, and glutelin) and squalene exhibit increased antioxidant activity, contributing to notable resistance to radiation and X-ray exposure. Bioactive compounds such as phytol, α-tocopherol, and a lunasin-like peptide (AhLun) with potential anticancer properties have also been identified in amaranth. Furthermore, six bioactive peptides were isolated and identified from amaranth, which, according to predictive models, demonstrate a high capacity to inhibit angiotensin-converting enzyme (ACE) activity, suggesting potential hypotensive effects. Certain amaranth peptides are considered promising functional food ingredients for the prevention and comprehensive treatment of conditions such as diabetes, inflammatory bowel diseases, hypercholesterolemia, cardiovascular diseases, and obesity. Amaranthus spp. and its processed products hold significant interest for the development of innovative food products, contributing to the expansion of their range and enhancement of nutritional value.

omega-Atracotoxin-Hv1a is an insect-specific neurotoxin whose phylogenetic specificity derives from its ability to antagonize insect, but not vertebrate, voltage-gated calcium channels. In order to help understand its mechanism of action and to enhance its utility as a lead compound for insecticide development, we used a combination of protein engineering and site-directed mutagenesis to probe the toxin for key functional regions. First, we constructed a Hairpinless mutant in which the C-terminal beta-hairpin, which is highly conserved in this family of neurotoxins, was excised without affecting the fold of the residual disulfide-rich core of the toxin. The Hairpinless mutant was devoid of insecticidal activity, indicating the functional importance of the hairpin. We subsequently developed a highly efficient system for production of recombinant toxin and then probed the hairpin for key functional residues using alanine-scanning mutagenesis followed by a second round of mutagenesis based on initial "hits" from the alanine scan. This revealed that two spatially proximal residues, Asn(27) and Arg(35), form a contiguous molecular surface that is essential for toxin activity. We propose that this surface of the beta-hairpin is a key site for interaction of the toxin with insect calcium channels.

Effects of roasting conditions on the properties of Amaranth (Amaranthus cruentus L.) grain using response surface methodology

Amaranth (Amaranthus hypochondriacus) is a pseudocereal with higher protein concentration than most cereal grains. Enzymatic hydrolysis and food processing could produce biopeptides from amaranth proteins; however, there is limited information about the bioactivity of peptides from amaranth proteins. The objective of this comprehensive review was to determine bioactive peptide sequences in amaranth proteins that may prevent cardiovascular disease, cancer, and diabetes. Amaranth proteins, reported in UniProt database, were evaluated for potential bioactive peptide using BIOPEP database. The 15 main proteins present in amaranth seed are 11S globulin, 7S globulin, α-amylase inhibitor, trypsin inhibitor, antimicrobial proteins, nonspecific lipid-transfer-protein-1, superoxide dismutase, ring-zinc finger protein, prosystemin, amaranth albumin 1, glucose-1-phosphate adenyltransferase, glucosyltransferase, polyamine oxidase, granule-bound starch synthase 1,and acetolactate synthase. All proteins showed high occurrence frequencies of angiotensin-converting enzyme-inhibitor peptides (A = 0.161 to 0.362), as well as of dipeptidyl peptidase IV inhibitor (A = 0.003 to 0.087). Other proteins showed antioxidative (A = 0.012 to 0.063) and glucose uptake-stimulating activity (A = 0.023 to 0.042), and also antithrombotic (A = 0.002 to 0.031) and anticancer sequences (A = 0.001 to 0.042). The results of this study support the concept that amaranth grain could be part of a "healthy" diet and thereby prevent chronic human diseases.

Amaranth proteins and peptides: Biological properties and food uses

Both poverty and malnutrition are serious problems in the world and both are interrelated. Food security for the poor depends on an adequate supply of food and/or the ability to purchase food. Unfortunately in the world today, more than 3.7 billion people are malnourished because of shortages of calories, protein, several vitamins, iron and iodine (World Health Organization, 2005; Rhodes, 2005). People can die because of shortage of any one of these nutrients or a combination of them. The total of 3.7 billion malnourished people is the largest number ever in history. In the world today, there are more than 6.5 billion humans (PRB, 2006). Based on current rates of increase, the world population is projected to double to more than 13 billion in about 58 years (PRB, 2006). At a time when the world population continues to expand at a rate of 1.2% per year, adding more than a quarter million people daily, providing adequate food becomes an increasingly difficult problem. Conceivably, the numbers of the malnourished will reach 5 billion in a few decades. Reports from the Food and Agriculture Organization of the United Nations and the US Department of Agriculture, as well as numerous other international organizations, further confirm the serious nature of the global food supply. For example, the per capita availability of world cereal grains, which make up 80% of the world's food supply, has been declining for more than two decades. This decline is taking place despite all the current agricultural and biotechnological facilities available. Malnourished people are more susceptible to numerous diseases, like malaria, tuberculosis, schistosomiasis and AIDS. The World Health Organization reports that there are more than 2.4 billion people infected with malaria, 2 billion infected with tuberculosis, 600 million infected with schistosomiasis and 40 million infected with AIDS (Pimentel et al., 2004). In this chapter, we will examine the need to increase and make more rational food production, to conserve natural resources, to reduce food (crop) losses to pests, to consider the possibility and benefits of converting annual grains into perennial grains and to consider new crops and innovative minilivestock.

Britto, D. T., Balkos, K. D., Becker, A., Coskun, D., Huynh, W. Q. and Kronzucker, H. J. 2014. Potassium and nitrogen poising: Physiological changes and biomass gains in rice and barley. Can. J. Plant Sci. 94: 1085–1089. Soil nitrogen, potassium, and water are three of the most important factors influencing, often interdependently, the growth of plants. Maximizing plant growth is not simply a matter of maximizing the availability of these and other nutrients; indeed, excess supply can be deleterious to plant performance. Rather, optimal performance may come about by adjusting the supply of each of the disparate factors required for plant growth, not only individually, but in relation to one another. In our work investigating the nutritional maximization of plant growth, we have found that altering the ratios of N and K provided to seedlings of cereal grasses can result in very substantial increases in vegetative biomass accrual, e.g., >220% of low-K+controls, in short-term studies with rice, the world's most important cereal grain, and even greater gains in grain yield, in the longer term. Hence, the findings in our laboratory are of direct relevance to the aim of NSERC's Green Crop Network, which was to contribute to the amelioration of climate change by improvement of carbon capture and sequestration in crop plants. In addition, these findings may help to increase the world's food supply, the security of which is sometimes at odds with proposed means to thwart climate change. Our work in this area has also led to a potential breakthrough of a more fundamental sort in plant nutritional biology, which may in itself have important practical implications: evidence that aquaporin-type transport proteins conduct rapid NH3fluxes into roots at toxic levels of external ammonia/ammonium.

Population Growth and the Environment: Planetary Stewardship David Pimental Cornell University Introduction During recent decades there has been a dramatic worldwide population increase. Based on current rates of increase of 1.5% per year, the world population is projected to double to more than 12 billion in about 46 years (Population Reference Board, 1996). The world population adds more than a quarter million people daily and this rapid growth is placing enormous pressure on the environment. The United States population doubled from 135 million to more than 270 million during the past 60 years and is projected to double again to 540 million in the next 70 years based on the current U.S. growth rate of 1% per year (United States Bureau of the Census, 1996). China's population is 1.2 billion and, despite the governmental policy of permitting only one child per couple, it is still growing at an annual rate of 1.1% (doubling time of 60 years) (PRB, 1996). India has nearly 1 billion people living on approximately one-third of the land of either the United States or China. India's current population growth rate is 1.9%, which translates to a doubling time of 37 years (PRB, 1996). Together, China and India constitute more than one-third of the total world population. Given the decline in resources, it is unlikely that India, China, and the world population in total will double. In the world today more than 2 billion humans are now malnourished, and this is the largest number of hungry humans ever recorded in history (Neisheim, 1993; Bouis, 1995; World Health Organization, 1995)! Conceivably the numbers of malnourished will reach 3 to 5 billion in future decades. Reports from the Food and Agriculture Organization of the United Nations and the U.S. Department of Agriculture, as well as numerous other international organization further confirm the serious nature of the global food supply (Royal Society and National Academy of Sciences, 1992; NAS, 1994). For example, the per capita availability of world cereal grains, which make up 80% of the world's food supply, has been declining for the past 15 years (Kendall and Pimentel, 1994; Harris,

Most of the world's food supply is derived from cereal grains that are borne in a unique structure called the spikelet, the fundamental unit of inflorescence architecture in all grasses. branched silkless1 (bd1) is a maize mutation that alters the identity of the spikelet meristem, causing indeterminate branches to form in place of spikelets. We show that bd1 encodes a putative ERF transcription factor that is conserved in different grasses and is expressed in a distinct domain of the spikelet meristem. Its expression pattern suggests that signaling pathways regulate meristem identity from lateral domains of the spikelet meristem.

Stored cereal crops form the major component of the world's food supply. It is well known that post-harvest crop losses, due to insects and microbes, cause significant economic waste in both developed and developing countries. In general, the environment in storage facilities is prone to rapid pest development, leading to significant grain losses. Rice weevil (Sitophilus oryzae L.) is one pest of cereal crops that deposits its eggs on or in a seed. To detect rice weevil in stored rice, we developed PCR-based molecular markers of Sitophilus oryzae. Several sets of PCR primers from the ‘internal transcribed spacer 2’ gene of S. oryzae were analyzed to identify molecular markers that are specific to the S. oryzae genome. Among six sets of molecular markers identified, three were found to be useful for identifying rice weevil. Our results demonstrate that a PCR marker system permits rapid and reliable identification of weevil in stored grain. Furthermore, this PCR assay would expand the choice of tools for monitoring populations of the weevil in pest management programmes.

Food security depends on available world supplies of food, the income of the designated population, and the population's access to the available supplies. Consequently, though seldom recognized in national food security policies, there is a direct relationship between food security, world trade in food, and the domestic policies that govern access to international markets for food. On all three scores, I believe we can be optimistic about improvements in world food security over the next quarter century. Over the next quarter century, the world's supply of food will grow somewhat more rapidly than will the demand for it, leading to lower real prices of food. Thus, the trend of food prices, as measured by grain prices, is likely to continue the trend of the current century, though at a slower rate of decline.' The remarkable reduction in the international price of grain that has occurred in this century is given all too little emphasis in discussions of the world food situation, certainly so in the discussions of the food pessimists. I am confident that the real per capita incomes of the majority of the population in the developing countries will continue to increase, contributing to an improvement in food security. Finally, I believe that, with the changes in agricultural policies in the major industrial countries, world trade in farm products, especially grains, will be further liberalized in the future. In addition, more and more developing countries are reducing barriers to trade, thus increasing access to world food supplies. Thus, all the broad trends point o an improvement in world food security and a reduction in the number of persons adversely affected by both long-term or short-term inadequate access to food. This does not mean that in every country food security will improve. Some governments may continue to follow national and trade policies related to food that restrict domestic food production, limit the growth of per capita incomes, and restrict access to the available world food supplies. When this happens, food security and adequacy will not be im roved or not improved as much as they po entially could be. At this time, there can be little doubt that the poor performance of agriculture and the insecurity of food supplies in sub-Saharan Africa over the past quarter century have been due primarily to inappropriate policies-to policies that discriminated against agriculture and resulted in large-scale governmental interventions in international trade. Misgovernment plus civil and ethnic wars have exacted and continue to exact a

The Recombinant DNA (rDNA) technique is expected to bring about a great progress in the improvement of breeding technology and the development of new plant varieties showing high quality and high yield, such as those with excellent pest and disease resistances, those with environmental stress tolerance, etc. In the USA, a late ripening tomato variety (FLAVR SAVRTM) developed through the rDNA technology was commercialized as the world's first recombinant food in 1994. Seven transgenic crop plants, such as herbicide tolerant soybean and canola, insect resistant corn and potato, were complied the all safety assessments with the guidelines required and they are marketable in Japan.General public, however, are not familiar with rDNA technology, and some seem to feel uncomfortable with biotechnology. It is caused by the difficulty of the technology and lacking of sufficient information. In order to promote agricultural biotechnology, it is important to give precise information about rDNA technology to general public so that they can comfortably accept biotechnology and the products. Because, the rDNA technique is an most important technology to improve world's food supply and global environment in the next century.

World Populationprovides the resources needed to understand the economic, demographic, and environmental issues at stake on a planet rushing toward "carrying capacity." World Population: A Reference Handbookpresents the latest facts regarding population problems and issues in countries all over the world. An overview of world population highlighting terms, demographic processes, and background information leads to a tour of world population history through census counts, plagues, famines, breakthroughs in disease control and birth control, and landmark judicial decisions. Biographies profile people who have worked to advance our understanding of world population issues or shaped population policy, such as M. S. Swaminathan, architect of India's "Green Revolution," who contributed to the expansion of the world's food supplies. A statistical chapter provides data on everything from the birth rate in Pakistan to AIDS orphans in the Caribbean, and a fascinating discussion of global trends for 2015 makes projections about world demographics, aging patterns, migration, and food.

Amaranth (Amaranthus spp.) is one of the few plant species where both leaves and grains can be consumed. Among the main species used as producers of edible grains are Amaranthus hypochondriacus, A. cruentus, A. caudatus, and A. mantegazzianus. The grains of these species are characterized by their protein content (13-18%), which has high nutritional value. Additionally, the different protein fractions of the amaranth grain have been shown to contain sequences of biologically active peptides (BAPs) with multiple beneficial bio-functionalities for health. Among these, we can highlight antihypertensive, antioxidant, antitumor, antidiabetic, antithrombotic, anticholesterolemic and immunomodulatory activities. The aim of this chapter is to describe the different biological functionalities of BAPs obtained from the proteins of the amaranth grain, which can be considered a promising natural source of therapeutic agents with potential use in the prevention and treatment of various chronic diseases.