Quinoa

Botany, Production and Uses

Atul Bhargava, Shilpi Srivastava

• Publisher: CAB International
• Year: 2013
• Print ISBN: 9781780642260
• eBook ISBN: 9781789244427
• Topic: Technology & Engineering
• Subtopic: Botany
• Index: Technology & Engineering

* Quinoa is an invaluable crop, highlighted by the FAO as one of the world's main crops for future food security* Timely publication – The year 2013 has been declared "The International Year of the Quinoa" (IYQ), recognizing the Andean indigenous peoples, who have maintained, controlled, protected and preserved quinoa as food for present and future generations thanks to their traditional knowledge and practices of living well in harmony with mother earth and nature.* Covers the history, phylogeny and systematics, botany and agrotechnology

1 Introduction

There are an estimated 7000 plant species that have been used as crop plants at some point in human history (FAO, 1998). However, today only 150 plant species are cultivated; just 12 of these provide approximately 75% of the world’s food and four produce over 50% of the world’s food (Bermejo and León, 1994). Prescott-Allen and Prescott-Allen (1990) state that common figures range from seven plant species providing 75% of human nutrition to 30 plant species providing 95% of human nutrition. These commonly utilized crops are intensively cultivated and require farm mechanization and increased inputs in the form of labour, high-yielding varieties, chemical fertilizers and pesticides (Bhargava et al., 2008, 2012). These accelerated inputs have resulted in intolerable pressure on fragile agroecosystems. Modern agriculture has increased homogeneity and mono-crop cultivation, resulting in loss of agrobiodiversity and frequent crop losses due to infestation by pathogens. The need of present times is a gradual shift from input-intensive to environmentally sound sustainable agriculture. Modelling of traditional farming systems to modern needs with increased organic linkages might be a good option for sustainability of the agricultural production system and maintenance of agroecological stability (Bhargava et al., 2008). This would also require a shift in focus towards increasing production by using agriculturally marginal lands for crops that are less exploited but that have immense potential for diverse uses (Partap et al., 1998).

The emphasis on a handful of major crops has narrowed the number of species on which global food security depends. The consequences of crop failures from unforeseen stresses, pests and diseases can be catastrophic (Prescott-Allen and Prescott-Allen, 1990). The past three decades have seen a wide range of research interests on underutilized crops and a number of significant programmes have been undertaken in both developing and developed countries to promote underutilized species for agricultural systems, as alternative crops or as sources of new products.

1.1 Underutilized Crops

Underutilized or neglected crop species are often indigenous ancient crop species that are still used at some level within the local, national or even international communities, but have the potential to contribute further to the mix of food sources (Mayes et al., 2011). These species appear to have considerable potential for use yet their potential is barely exploited, if not totally neglected, in agricultural production. Many underutilized crops were once more widely grown but are today falling into disuse for a variety of agronomic, genetic, economic and cultural reasons (Hammer et al., 2001). Farmers and consumers are using these crops less because they are not competitive with other crop species in the same agricultural environment. Orphan, abandoned, new, underutilized, neglected, lost, under-used, local, minor, traditional, forgotten, alternative, niche, promising, underdeveloped: these and other terms are often used as synonyms for underutilized species (Padulosi and Hoeschle-Zeledon, 2004). Underutilized crops are often known as ‘new crops’, not because they are ‘new’ but because they have been taken up by agricultural researchers and commercial companies for a new market. The main features of the underutilized crops are that they are:

• important in local consumption and production systems;

• highly adapted to agroecological niches and marginal areas;

• represented by ecotypes or landraces;

• cultivated and utilized drawing on indigenous knowledge;

• characterized by fragile or non-existent seed supply systems;

• hardly represented in ex situ gene banks and

• ignored by policy makers and excluded from research and development agendas (Padulosi and Hoeschle-Zeledon, 2004).

Moreover, the limited information available on many important and frequently basic aspects of neglected and underutilized crops hinders their development and sustainable conservation (Hammer et al., 2001).

Many wild and underutilized plants have potential for more widespread use and could contribute to food security, agricultural diversification and income generation (Vietmeyer, 1986; Anthony et al., 1995). Neglected and underutilized crops represent an important source of revenue for local economies and are part of the rich cultural and traditional heritage of communities around the world (IAEA, 2004). In addition to this, these crops are important sources of resistance genes for biotic and abiotic stress breeding that can also be used for the genetic improvement of crops. Compared with the major crops, they require relatively low inputs and, therefore, contribute to sustainable agricultural production. Underutilized crops have great potential to alleviate hunger directly, through increasing food production in challenging environments where major crops are severely limited, through nutritional enhancement to diets focused on staples and through providing the poor with purchasing power, helping them buy the food that is available (Mayes et al., 2011).

1.2 Chenopodium as an Underutilized Plant

Among a number of underutilized species, members of the genus Chenopodium (family Amaranthaceae) are most promising since they have the ability to thrive and flourish under stressful conditions (Bhargava et al., 2003, 2006a; Jacobsen et al., 2003a) as well as on soils with minimum agricultural inputs. Many complex adaptive modifications related to breeding system, seed dispersal and their germination account for the success of the members of this genus in colonizing disturbed habitats (Williams and Harper, 1965; Dostalek, 1987). With a shift in focus towards production on agriculturally marginal lands, Chenopodium has a significant role to play both as a nutritious food crop and as a cash crop. The genus Chenopodium, commonly known as ‘goosefoot’, comprises about 250 species (Giusti, 1970) that include herbaceous, suffrutescent and arborescent perennials, although most species are colonizing annuals (Wilson, 1990). Some well-known species include C. quinoa, C. pallidicaule, C. berlandieri ssp. nuttalliae, C. ambrosioides, C. murale and C. amaranticolor. Chenopodium spp. have been cultivated for centuries as a leafy vegetable and subsidiary grain crop in different parts of the world (Risi and Galwey, 1984). Although only three species (C. quinoa, C. pallidicaule and C. berlandieri subsp. nuttalliae) are reported to be cultivated (Heiser and Nelson, 1974; Wilson, 1980; Bhargava et al., 2006a, 2007), the leaves and tender stems of numerous other species are consumed as food and fodder (Tanaka, 1976; Kunkel, 1984; Partap, 1990; Moerman, 1998; Partap et al., 1998). The foliage of Chenopodium is an inexpensive and rich source of protein, carotenoids and vitamin C (Koziol, 1992; Prakash et al., 1993; Bhargava et al., 2006a). The protein has a balanced amino acid spectrum with high lysine (5.1–6.4%) and methionine (0.4–1.0%) contents (Prakash and Pal, 1998; Bhargava et al., 2006a).

1.3 Quinoa

Of all the new-world crops, Chenopodium quinoa Willd., commonly known as ‘quinoa’, is one of the most underutilized, given its superb seed protein composition and yield potential. It is principally a grain crop, harvested and consumed in a manner similar to that for cereal grains, although its leaves are also used as a potherb (Maughan et al., 2007). Quinoa is not a true cereal grain, but rather is a pseudocereal, which is dicotyledonous. In contrast, cereals are monocotyledonous (Valencia-Chamorro, 2003). Quinoa has risen from a neglected subsistence crop of indigenous farmers to become a major export of the Andean nations of Bolivia and Peru within the past 20 years (Jellen et al., 2011). The emergence of quinoa to prominence in organic food markets of the developed world has led to scientists giving increasing attention to the crop’s unique nutritional benefits, and potentially novel abiotic stress-tolerance mechanisms.

Quinoa is a native of the Andean region and has been cultivated in the region for around 7000 years (Garcia, 2003). Quinoa was known by a number of names in local languages. The people of the Chibcha (Bogota) culture called quinoa ‘suba’ or ‘supha’, while the Tiahuancotas (Bolivia) called it ‘jupha’ and the inhabitants of the Atacama desert knew it by the name ‘dahue’ (Pulgar-Vidal, 1954). León (1964) is of the view that the names ‘quinoa’ and ‘quinua’ were used in Bolivia, Peru, Ecuador, Argentina and Chile. The crop has been an important food grain source in the Andean region since 3000 BC (Tapia, 1982) and occupied a place of prominence in the Inca Empire only next only to maize (Cusack, 1984). However, after the conquest of the region by the Spaniards in 1532, other crops, such as potato and barley, relegated quinoa to the background (Bhargava et al., 2006a). However, the sporadic failure of green revolution in the Andes and enormous destruction of other crops by droughts, once again brought native crops like quinoa to the forefront as it showed much less fall in the yields in severe conditions (Cusack, 1984). In the mid-1970s, the exceptional nutritional characteristics of quinoa were discovered and its popularity began to increase (Maughan et al., 2007). Andean countries established small but effective breeding programmes and several new varieties were released. Efforts were made to collect diverse landraces to prevent genetic erosion, resulting in national quinoa germplasm banks in many Andean countries, with the largest banks being in Bolivia and Peru (Maughan et al., 2007).

Quinoa is grown in a wide range of environments in the South American region (especially in and around the Andes), at latitudes from 20°N in Colombia to 40°S in Chile, and from sea level to an altitude of 3800 m (Risi and Galwey, 1989). Recently it has been introduced in Europe, North America, Asia and Africa. Many European countries are members in the project entitled ‘Quinoa – A multipurpose crop for EC’s agricultural diversification’, which was approved in 1993 (Bhargava et al., 2006a). The American and European tests of quinoa have yielded good results and demonstrate the potential of quinoa as a grain and fodder crop (Mujica et al., 2001; Casini, 2002; Jacobsen, 2003; Bhargava et al., 2006a).

1.3.1 Nutritional importance of quinoa

The nutritional excellence of quinoa has been known since ancient times in the Inca Empire. The importance that quinoa could play in nutrition has been emphasized not only in developing countries but also in the developed world. Quinoa seeds have a higher nutritive value than most cereal grains and contain high-quality protein and large amounts of carbohydrates, fat, vitamins and minerals. Perisperm, embryo and endosperm are the three areas where reserve food is stored in quinoa seed (Prego et al., 1998).

The mean protein content reported for quinoa grain is 12–23% (González et al., 1989; Koziol, 1992; Ruales and Nair, 1994a, 1994b; Ando et al., 2002; Karyotis et al., 2003; Abugoch, 2009), which is higher than that of barley, rice or maize, and is comparable to that of wheat (USDA, 2005; Abugoch, 2009). Moreover, the essential amino acid balance is excellent because of a wide range of amino acids, with higher lysine (5.1–6.4%) and methionine (0.4–1%) contents (Prakash and Pal, 1998; Bhargava et al., 2003, 2006a; Abugoch, 2009). Quinoa protein can supply around 180% of the histidine, 274% of the isoleucine, 338% of the lysine, 212% of the methionine + cysteine, 320% of the phenylalanine + tyrosine, 331% of the threonine, 228% of the tryptophan and 323% of the valine recommended by FAO/WHO/UNU in protein sources for adult nutrition (Vega-Gálvez et al., 2010). Starch is the most important carbohydrate in quinoa grains, making up approximately 58.1–64.2% of the dry matter (Repo-Carrasco et al., 2003). Quinoa starch consists of two polysaccharides: amylose and amylopectin. The amylase content of quinoa starch varies between 3% and 20%, while the amylose fraction of quinoa starch is quite low (Abugoch, 2009). The starch of quinoa is highly branched, with a minimum degree of polymerization of 4600 glucan units, a maximum of 161,000 and a weighted average of 70,000 (Praznik et al., 1999). Granules of quinoa starch have a polygonal form, with a diameter of 2 μm, being smaller than starch of the common grains (Vega-Gálvez et al., 2010). The total dietary fibre of quinoa is near that of cereals (7–9.7% by difference, db), and the soluble fibre content is reported between 1.3% and 6.1% (db) (Ranhotra et al., 1993; USDA, 2005).

The ash content of quinoa (3.4%) is higher than that of rice (0.5%), wheat (1.8%) and other traditional cereals (Cardozo and Tapia, 1979). Quinoa grains contain large amounts of minerals like Ca, Fe, Zn, Cu and Mn (Repo-Carrasco et al., 2003). Calcium (874 mg/kg) and iron (81 mg/kg) in the seeds are significantly higher than most commonly used cereals (Ruales and Nair, 1992). Minerals like P, K and Mg are located in the embryo, while Ca and P in the pericarp are associated with pectic compounds of the cell wall (Konishi et al., 2004). The abundant mineral content makes the grains valuable for children and adults who can benefit from calcium for bones and from iron for blood functions (Konishi et al., 2004).

The oil content in quinoa ranges from 1.8 to 9.5%, with an average of 5.0–7.2% (DeBruin, 1964; Koziol, 1990) that is higher than that of maize (3–4%). Quinoa oil is rich in essential fatty acids such as linoleate and linolenate (Koziol, 1990) and has a high concentration of natural antioxidants like α-tocopherol and γ-tocopherol (Repo-Carrasco et al., 2003). The antioxidant activity of quinoa could be of particular interest to medical researchers and needs more attention (Bhargava et al., 2006a).

Few reports are available on the vitamin content of quinoa grain. Ruales and Nair (1992) reported appreciable amounts of thiamin (0.4 mg/100 g), folic acid (78.1 mg/100 g) and vitamin C (16.4 mg/100 g). Koziol (1992) gave riboflavin and carotene content as 0.39 mg/100 g and 0.39 mg/100 g respectively, and concluded that quinoa contains substantially more riboflavin (B₂), α-tocopherol (vitamin E) and carotene than wheat, rice and barley. In a 100 g edible portion, quinoa supplies 0.20 mg vitamin B₆, 0.61 mg pantothenic acid, 23.5 μg folic acid and 7.1 μg biotin (Koziol, 1992). Recent reports have also confirmed that quinoa is rich in vitamins A, B₂ and E (Repo-Carrasco et al., 2003).

However, several antinutritional substances such as saponins, phytic acid, tannins and protease inhibitors have been found in quinoa seed, which can have a negative effect on the performance and survival of monogastric animals when it is used as the primary dietary energy source (Vega-Gálvez et al., 2010).

The leaves of quinoa contain ample amount of ash (3.3%), fibre (1.9%), vitamin E (2.9 mg α-TE/100 g) and Na (289 mg/100 g) (Koziol, 1992)....

Table of contents

• Cover Page
• Dedication
• Title Page
• Copyright Page
• Contents
• Contributors
• Preface
• Acknowledgements
• Part I – Introduction and History
• Part II – Phylogeny and Systematics
• Part III – Botany and Agrotechnology
• Part IV – Qualitative Aspects, Economics and Marketing
• Index