1. Introduction

Since 1998, the WHO has considered obesity as an epidemic affecting the globe, a condition related to more deaths than undernutrition in the whole planet. Obesity is associated with various noncommunicable diseases (NCD) such as cardiovascular diseases, cancer and diabetes, among others. Globally, two out of three deaths each year are attributable to NCD. In this context, it is very important to take into account some alimentary traditions and the social value of food practices that have been lost with time. Most of the traditional culinary practices, beliefs, attitudes and meanings of certain foods have been neglected and traditional crops have been left aside, missing the food cultural practices of different regions.

© The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons © 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and eproduction in any medium, provided the original work is properly cited.

An outstanding food crop that has been almost lost is quinoa (Chenopodium quinoa Willdenow), a South American dicotyledonous primary crop (an indehiscent achene: a seed-like fruit with a hard coat) that has become an extremely popular food product in the last decades. The seeds (approximately 2.5 mm in length and 1.0 mm in diameter) are flat white, yellow, red, brown and black, whereas the seed coats have a brown color and possess excellent nutritional properties (Figures 1 and 2).

#### 1.1. Quinoa plant: origin and botanical properties

Chenopodium quinoa Willd. is an annual gynomonoecious plant with an erect stem, alternate leaves and flowers clustered together to form the inflorescence in a panicle that measures from 15 to 70 cm long [1]. The basic chromosome number of quinoa is x = 9 and their somatic chromosome number is 2n = 4x =36, suggesting that it is an allotetraploid plant [2]. Measurements of chromosome arm length ratios in quinoa indicate an allopolyploid, which is consistent with it high degree of self-fertility and low levels of inbreeding depression seen in this species [3].

Figure 1. Chilean quinoa plants.

Figure 2. Collected seeds of quinoa.

An outstanding food crop that has been almost lost is quinoa (Chenopodium quinoa Willdenow), a South American dicotyledonous primary crop (an indehiscent achene: a seed-like fruit with a hard coat) that has become an extremely popular food product in the last decades. The seeds (approximately 2.5 mm in length and 1.0 mm in diameter) are flat white, yellow, red, brown and black, whereas the seed coats have a brown color and possess excellent nutritional prop-

Chenopodium quinoa Willd. is an annual gynomonoecious plant with an erect stem, alternate leaves and flowers clustered together to form the inflorescence in a panicle that measures from 15 to 70 cm long [1]. The basic chromosome number of quinoa is x = 9 and their somatic chromosome number is 2n = 4x =36, suggesting that it is an allotetraploid plant [2]. Measurements of chromosome arm length ratios in quinoa indicate an allopolyploid, which is consistent with it high degree of self-fertility and low levels of inbreeding depression seen in this

erties (Figures 1 and 2).

species [3].

Figure 1. Chilean quinoa plants.

1.1. Quinoa plant: origin and botanical properties

38 Superfood and Functional Food - An Overview of Their Processing and Utilization

Quinoa was one of the basic foods in pre-Hispanic communities of the Andean Region, grown for over 7000 years mainly in the current locations of Peru, Bolivia, Ecuador, Chile, Argentina and Colombia, from 2° North latitude (Colombia) to 47° South latitude (Chile) [4–6]. The name refers to "the mother grain" by the Andean people and it was used not only as a food but also for medicinal purposes. The colonists suppressed its cultivation and the remaining crops that survived were cultivated practically hidden in small areas [7]. The locals have preserved quinoa in its natural state, including its many varieties, as food for present and future generations.

Quinoa represents a cultural heritage in many Latin-American countries. It has survived from extinction in different agroecological zones, ranging from the extremely dry Altiplano highlands at 4000 m above sea level with average rainfall of 150 mm per year to coastal zones of central and southern Chile, where soils are clayish and rainfall is above 1000 mm/year [8]. It spread throughout the central and north-central Andean valleys and southwards into the Araucanian coastal region and adjacent Patagonia, diversifying into its five principal ecotypes. The crop is produced mainly in Bolivia, Peru and Ecuador, with efforts to cultivate it worldwide and the diversity has been described by five major ecotypes linked to the geographical region: Altiplano (Peru and Bolivia), Inter-Andean valleys (Bolivia, Colombia, Ecuador and Peru), Salt lands (Bolivia, Chile and Argentina), Yunga (Peru, Bolivia and Argentina) and Coastal (Chile) [9, 10].

Miranda et al. [11] observed genetic differentiation among the geographic distribution of quinoa genotypes, which were expressed in morphological, yield responses, chemical composition and functional properties in a common garden assay of six selected genotypes. Using this model, the high capacity of adaptation of the seeds to different environments has been demonstrated [12]. Moreover, these properties of quinoa seeds allow this crop to be used under environmental extreme conditions in countries facing challenges such as drought and salinity under very diverse agroclimatic conditions globally [1].

There are currently more than 6000 varieties of quinoa cultivated by farmers [13]. Due to the wide range of genotypes (including 250 varieties), the possibilities of adaptation to many abiotic stresses abroad have increased significantly the interest of quinoa cultivation [14]. The plant exhibits an enormous adaptability to different environments, including the harsh conditions that characterize much of the Andean zone. Therefore, the production has spread through many different countries, including Japan, Australia, Spain, Germany, England, Sweden, Denmark, the Netherlands, Italy, France, Finland, Kenya, Ethiopia, India, the USA, Canada, among others. Many reports indicate that quinoa is an interesting alternative crop for the use of deteriorated and poor soils [5] and it has been successfully tested in various countries in Asia, the Near East and North Africa [6]. In fact, the enormous plasticity of quinoa includes tolerance to frost, salinity and drought, it has the ability to grow on marginal and arid soils and is also adapted to high altitudes [15–18]. The strong tolerance to drought and salinity allows it to resist the current and future challenges of the global climate change, including water shortage [15]. The plant adapts well to climates ranging from desert dry weather to relative humidity from 40 to 88%, with temperatures from −4°C to 38°C.

Several genotypes of quinoa are able to maintain a high photosynthetic efficiency under waterdeficit conditions [19, 20] and to quickly reestablish photosynthesis after a period of rehydration [21–24]. Quinoa shows an extraordinary physiology of adaptation to stress, particularly its highly efficient use of water [8], that is, the quantity of grain obtained per liter of water used is another useful criterion for comparing quinoa with cereals. Martinez [25] reported 500 L water per kilogram quinoa, a significantly lower water-use footprint compared with rice (2497 L/kg) or maize (1222 L/kg), figures that are even greater if one considers also quantity of protein per kilogram. Crop production is acceptable with rain amounts of 100–200 mm [26]. The drought tolerance of quinoa has been attributed to a reduction in leaf area [23, 24, 27], the presence of calcium oxalate vesicles in leaves, which could reduce the transpiration rate [22, 28] and their branched and dense root system, which is able to penetrate into 1.5 m sandy soil [22, 27].

Regarding the metabolism of quinoa during periods of drought stress, it has been suggested that the induction of antioxidant molecules related with nitrogen metabolism is very important [29]. In fact, drought increases the amount of glutamine in quinoa leaves, which is the main form in which nitrogen is translocated to the grains [30]. Therefore, drought stress episodes increase the content of various amino acids, including Phe, Val, Trp and Met. These changes in quality could compensate the decline of the seed yield under stressful conditions. It has been suggested that the ornithine cycle and induction of amino acids could play a key role in the response to water scarcity and subsequent restoration under conditions of rehydration [29, 30]. Moreover, the aromatic amino acids Phe, Tyr and Trp are the main precursors of bioactive secondary metabolites, including the biosynthesis of flavonoids and alkaloids [31], most of which exhibit healthy properties [32]. The physiological relationship between the induction of amino acid synthesis and the production of healthy secondary metabolites is under investigation.
