An extricable link between biodiversity and nutrition security has been magnified by many researchers over the past three decades as humans have utilized more than 10,000 edible species from the totally expected to be 300,000 plant species. A strong reliance on handful of major crops has inherent agronomic, ecological, and nutritional risks and is probably unsustainable in the long run. On the other hand, global food production is still a main challenge for the future of mankind. New strategies such as the exploration and utilization of underutilized crops have been affirmed as some of the promising fields to meet world food needs. As such crop, amaranth (Amaranthus spp.) has the potential to be prospected as potential plant in alleviating malnutrition in most of the developing countries, especially in Indonesia (location: 6oN to 11oS and from 95oW to 141°E) also known as the biggest archipelago country in the world. Malnutrition with its two constituents of protein-energy malnutrition and micronutrient deficiencies has been recognized as a persisting public health challenge in many developing countries, e.g., Africa, Asia, and Indonesia. This paper highlights the advantage of amaranth in terms of their nutrition and further application in nutraceuticals.
- weedy types
An extricable link between biodiversity and nutrition security has been magnified by many researchers over the past three decades as human has utilized more than 10,000 edible species from the totally expected to be 300,000 plant species. Nevertheless, there are only few or up to 150 of those edible ones that have been commercialized significantly on the global scale. Among huge alternative crops existing, humans depend only on 12 plant species that supply dietary energy with a strong dependency on 4 species only, namely, rice, wheat, maize, and potato. Thus, reliance on handful of major crops has inherent agronomic, ecological, and nutritional risks and is probably unsustainable in the long run .
On the other hand, global food production is still a main challenge for the future of mankind. Rapid deforestation, feeding the world population, and climate change have made it to be much more challenging . The dramatic decline of tropical rain forests and habitat destruction aiming for settlement, cash crop plantation such as oil palm and rubber, and building of infrastructures would lead to massive biodiversity loss. This consequently would adversely affect human’s life quality . While the area of planting has been dramatically reduced, on the opposite, the agricultural production is expected to be increased by 70% as a result of a 40% increase in world population . The impact of climate change for most of the developing countries would exacerbate the food security challenges due to higher frequency of droughts and flood .
2. Potential of underutilized crops
It is mainly known that almost 900 million people are hungry worldwide. In adjacent to that, 195 million children under 5 years of age are stunted. Of this total number, 90% live in 36 countries, mostly in the developing ones . New strategies such as the exploration and utilization of underutilized crops as well their genetic assessment and plant genetic diversity interlinked with plant breeding have been affirmed as some of the promising fields to meet the world food needs . Thus, re-directing the global agricultural system to ensure better nutrition is critical. The current global trend in agricultural system produces enough food quantitatively in total; however, the rapidly growing population demands not only an increase in quantity but also in terms of highly nutritious food with good protein quality [4, 5]. In regard to this, it is imperative that both researchers and development professionals apply new and sustainable approaches to enhance the quality and to increase the variety of food produced and consumed around the world. Other innovative methodologies embedded in agriculture and food science will also be essential to upscale dietary diversity and nutrition .
Over the past two decades, moreover, nutraceuticals have been much more explored as some vegetables and fruits bear great potential to be further prospected as antioxidant, anticancer, anti-allergic, and antihypertensive agent and as a food for patients with autoimmune diseases . Thus, an alternative approach other than the major staple crops, valorization of valuable, however underutilized, crops have been in the focus of many (food) researchers and agronomists . In many areas, such underutilized particularly the weedy edible types have been playing a major role in fulfilling the micro- and macronutrients and protein requirements . Therefore, this paper highlights the potential and utilization of
Indonesia—the biggest world archipelago—is located at the tropical equator and situated between the Indian and Pacific oceans and the Asian and Australian continent. It extends from latitudes 6oN to 11oS and from 95oW to 141°E. The greatest distance from west to east and north to south is 5110 km and 1888 km, respectively . The archipelago consists of almost 17,504 islands, with five major islands, namely,
Almost 65% of its population live in rural areas and depend highly their livelihood on the agricultural basis activities as one of the five biggest
The major crops grown in Indonesia are rice, maize, soybean, peanut, cassava, and chili; meanwhile, the major vegetables grown in the country are chili; yard-long bean; cabbage; kidney bean; cucumber; Chinese cabbage; green mustard; amaranth (
It is also accounted as the fourth biggest world population with 270,054,853 people. The population is unevenly dispersed within the archipelago. There are 32 provinces stretching from Aceh to Irian Jaya; however, about 60% of it resides on Java—the smallest island among the big five—but Kalimantan which accounts for 28% of Indonesia’s total land area, as a matter of fact, is home to only 5% if the total population. The population density on Java is about 800–1000 people per km2, but Irian Jaya has only 7 people per km2 . In terms of economic, Indonesia is classified as one of the three biggest Southeast Asian countries—after Singapore and Malaysia—with a vibrant economic growth, namely, in the range of 5.1%, yearly .
The United Nations Food and Agriculture Organization (UN-FAO) agrees that to secure access for all to adequate supplies of food that is healthy, safe, and of high quality, and to do so in an environmentally sustainable manner. Nevertheless, with the rapidly growing population, how our current global food system will sustain itself remains a challenge. Additional (man-made) external factors, such as climate change, urbanization, social conflict including refugee from war-inflicted countries mostly in Africa and in the Middle East, extreme poverty, as well as overly stressed ecosystems and biodiversity, make it more obvious that there has never been a more urgent time for collective action to address food and nutrition security at the global stage .
In terms of biodiversity richness, Indonesia is counted as the second biggest biodiversity
Malnutrition with its two constituents of protein-energy malnutrition and micronutrient deficiencies has been recognized as a persisting public health challenge in many developing countries, e.g. in Africa, Asia, and including Indonesia. It is the direct cause of about 300,000 deaths per year and is indirectly responsible for about half of all deaths in young children. Certainly, poverty, political and economic situation in one country, and unhealthy environment including bad sanitation have worsened the problem . Moreover, the loss affected due to malnutrition in Indonesia has been estimated to be 2–3% of Indonesia’s gross domestic products or GDP or equal to more than US$ 5 billion yearly as a result of poor education standard, low IQ score, reduced productivity over time, and diminishing physical capability.
The physical condition of malnourished children is indicated generally with wasting and stunting. Wasting children loss their weight progressively. Chronical weight loss among children leads to stunting. It has been reported that over the past 6 years, the stunting situation has not yet been improved as there are 37% children under 5 years in Indonesia are malnourished, while more than 12% of children are suffering from wasting; with most of them live in the rural areas . According to a USDA-based technical report, Indonesia is on an “alert” regarding the malnutrition among children under 5 years of age as indicated with the orange color (Figure 1). Furthermore, the highest prevalence number was found on the drier part of Indonesia such as East Nusa Tenggara with up to 58% .
4. What is amaranth?
The family of
The utilization of amaranths depends greatly on geographical preferences. People on the humid tropical continents such as Asia and Africa use the young and succulent leaves as vegetables, meanwhile people on the northern hemisphere consume the grain amaranths. Due to its vivid color, amaranths are also cultivated as ornamentals. Most amaranth is mainly found in the form of weedy types including true weeds such as
Several morphological studies have been conducted in order to clarify its taxonomy, and several systematic botanical revisions based on leaf anatomy and morphology, pericarp structure, stem morphology, and anatomy have been also proposed . A high variability of morphological variation and high nutritional qualities were reported in the Indonesian weedy accessions, particularly the
In terms of its adaptability, amaranth possesses wide adaptability due to its
5. Nutritional values in amaranth
The incorporation of high-protein and mineral-containing crop would improve dietary diversification and enhance food quality or nutritional values. Amaranth is acknowledged as rich and inexpensive source of dietary fiber, mineral, vitamins, protein, and antioxidants . As it has been highlighted previously that there are up to 70 species included in the genus, however, only 17 species are classified as edible, and they accounted as the most important leafy vegetables with excellent nutrition for the lowland tropics of Africa and Asia .
From the agronomical point of view, amaranth can be grown successfully under varied soil and agroclimatic conditions of tropical lowlands with an elevation ranging from 100 to 800 m
Amaranth in Indonesia is very popular and ranked as the third mostly produced green leafy vegetables. The number of amaranth’s production is ranked as the third in Indonesia (Figure 2). Vegetable amaranth is part of the Indonesian’s daily dishes, and its taste resemblance to that of spinach. It is mostly cultivated on small plots less than one hectare belonging to subsistence farmer. The plots are located along the riverside or open fields scattered at the periphery of suburban areas and can be harvested within an interval of 4 to 6 weeks per harvest season. The yield is in the range of 2–5 tons ha-1 per harvest season, but it is available throughout the year, frequently traded in Indonesian traditional markets and usually sold in small bundles consisting of 10–20 plants. Growing amaranth is counted as one of the economically important vegetables in Indonesia. Moreover, vegetable amaranths provide a high concentration of vitamin A, and their nutritional benefit was incorporated by the eradication of children’s dark blindness in 1973–1980 in Indonesia .
Siemonsma and Piluek in  estimated that up to 225 primary use vegetables and more than 100 wild species exist, including a large number of weedy companions. The high biodiversity in Indonesia may open opportunities for breeding new type of amaranths with desired characters such as high-protein content. In terms of protein nutritional quality, some parameters, such as protein digestibility, available lysine, protein utilization, and the composition of well-balanced essential amino acid in food sources, especially the availability of lysine, methionine, and tryptophan, are counted as important aspects . Generally, vegetable amaranths have received lower attention than the grain ones . Although their nutritional superiority is not too much distinct from the grain ones as the leaves of amaranths were found to be a good source for lysine, which is required during the growth of young children or under 5 years old.
Research on the extent of the diversity of amaranths aiming to choose some of the weedy types as prospective genetic resources for useful traits has been conducted. The work reported the superiority of weedy edible amaranths harvested in the wild of Gayo Highlands, such as
Furthermore, a large number of trace elements such as iron (
Despite the health positive benefit effects exhibited in Amaranth, the anti-nutritive content such as oxalate and nitrate might be the hindrances in exploiting amaranth as food resource. The leaves were reported to have a relatively high amount of oxalate, which is in the range of 7.8–12.0 mg g−1 and 1.8–4.4 mg g−1 of nitrate. Although it is known that the level of toxicity of oxalate is quite low and a minimal lethal dose for humans is considered to be in the range of 5 g for an adult, vegetables are mostly found as the source of high levels of nitrate because the content of this salt could reach up to 3.25%. Such high values might be harmful to humans as nitrate has been described as potential carcinogenic via transforming first to nitrite and then to nitrosamine . Therefore, cooking properly and discarding water from boiling the vegetables might be counted as preventive measurement.
6. Nutraceuticals in amaranth
Amaranth can be grown for their seeds and are called as grain amaranths. The three most representing are
The medicinal importance of amaranth has been known since the ancient time. In Russia, it has been applied as a mixture with tea as it can be used in prophylactic and therapeutic purposes as well as applied in stomach cleaning, diuretic, cough, headaches, and tumor. These advantageous health effects are often attributed to different antioxidant components . Antioxidants are recognized as important nutraceuticals, which bring health-positive impacts because of phenolic compounds that are attributed with radical-scavenging activity . The oil in amaranth is an important source as an effective natural antioxidant supplement as it contains a relatively high amount of unsaturated fatty acids—such as linoleic acid, oleic acid, a small amount of linolenic acid, and a unique presence of squalene. Thus amaranth oil can be applied as supplements and beneficial for correcting hyperglycemia as part of an antioxidant therapy . Another
The seed flour of
Moreover, tocopherols (counterparts of vitamin E) and tocotrienols available in the seed are also closely linked with antitumor activity, antioxidant activity, cholesterol-reducing agent, and serum cholesterol regulatory levels that may reduce the synthesis of low density lipoprotein cholesterol between 30 and 70% attributed with the oil of
Amaranth, which is originated in America, has a wide ecogeographical distribution. It is a multipurpose plant, whose succulent leaves are tasty and tender, while its grains are consumed as cereals. Both plant parts are edible and can have an extraordinary amount of protein and essential amino acids, especially the lysine. This is found in very limiting numbers especially among the true cereal plants; due to this excellent nutritional character, amaranth can be prospected as a potential plant for the twenty-first century in combating malnutrition problem in many developing countries, especially in Indonesia. Indonesia, as the third big biodiverse-rich country in the world that also faces the malnutrition problem, especially among young children, should utilize the untapped genetic variation richness of
This research was conducted in Japan during 2010–2013 under the support from the Japanese
Conflict of interest
The authors declare no conflict of interest.