Functional and Bioactive Properties of Quinoa and Amaranth

Abstract

Antioxidant activity, antihypertensive activity and allergenicity of quinoa and amaranth were investigated and compared with those of seven cereals: buckwheat, barley, wheat, rice, foxtail millet, Japanese millet and millet. The radical scavenging activities of quinoa and amaranth were 42.3 and 22.6 mg gallic acid equivalent/g, respectively; thus, the pseudocereals have stronger radical scavenging ability than cereals. On the other hand, the antioxidant ability against linoleic acid was not very strong. Quinoa exhibited high angiotensin I converting enzyme (ACE) inhibition activity, which was equal to that of buckwheat. The ACE inhibition activity of amaranth was lower than that of quinoa, but higher than that of rice and wheat. Quinoa and amaranth did not show a positive reaction band against wheat protein antibodies.Keywords: angiotensin I converting enzyme inhibition, allergenicity, amaranth, antioxidant activity, quinoa *To whom correspondence should be addressed. E-mail: kwatanabe@nara.kindai.ac.jp IntroductionQuinoa (Chenopodium quinoa Willd) and amaranth (Amaranthus hypochondriacus) are known as pseudocereals. They have been described as "the grains of the 21st century" (Schlick and Bubenheim, 1996;Konishi, 2002). Their grains and flours are utilized as foodstuffs. Moreover, their proteins have high nutritional value because the higher levels of lysine compared to cereals such as rice and wheat, in addition to its high amino acid score (Ranhotra et al., 1993;Watanabe et al., 2003). Starch is a major component of these pseudocereals. Starch granules exhibit the A-type X-ray diffraction pattern which is common to most cereal starch (Inouchi et al., 1999;Ando et al., 2002). Therefore, quinoa and amaranth flours are used as substitutes for wheat flour in the production of bread, crackers, snacks and pasta (Morita et al., 1998;Caperuto et al., 2000;Chavez-Jauregui et al., 2000;Morita et al., 2001).Interest has recently increased in food that can protect against diseases such as diabetes, hypertension, hypercholesterolemia, allergy, atherosclerosis and cancers. There have been reports on the functional properties of quinoa and amaranth, including their suppressive effects on increased blood pressure (Ogawa et al., 2001;Silva-Sanchez et al., 2008), decreased serum and liver cholesterol levels (Takao et al., 2005) and antioxidant activity (Nsimba et al., 2008). However, there have been no reports comparing the functional properties of pseudocereals with those of other cereals. The objective of this research was to investigate the functional properties, including antioxidant activity, antihypertensive activity and non-allergenicity, of quinoa and amaranth, compared with those of other cereals. Materials and MethodsMaterials Quinoa and amaranth flours made from whole grains were gifts from Asai Co., Ltd. (Nagoya, Japan), and Shinkyosangyo Co., Ltd. (Tokyo, Japan), respectively. Barley (Hordeum vulgare L.), foxtail millet (Setaria italica L.), rice (Oryza sativa L.), Japanese millet (Echinochloa esculenta H.) and mi...

Amino Acid Composition, Oxidative Stability, and Consumer Acceptance of Cookies Made with Quinoa Flour

“…This result was identical to those measured previously by the ferric thiocyanate and 1,1-diphenyl-2-picrylhydrazine (DPPH) methods (Asao and Watanabe, 2010). The antioxidant capacity of quinoa flour was high compared to wheat flour.…”

“…A discrepancy in the evaluation of antioxidant activity between the ORAC assay and conventional methods such as the DPPH assay has been raised (Ichimori, 2012;Kanno et al, 2013). However, the ORAC assay used in this work gave results identical to those using conventional methods (Asao and Watanabe, 2010) in the evaluation of the antioxidant capacity of pseudocereals and cereals (Fig. 1).…”

“…stable due to the presence of vitamin E, which acts as an antioxidant (Carrasco et al, 2003;Ng et al, 2007). The antioxidant activity against the lipids in quinoa was high compared with wheat (Asao and Watanabe, 2010). It was therefore suggested that quinoa contributes to the oxidative stability of food.…”

“…Pasta and bread made with quinoa flour have been reported (Caperuto et al, 2001;Stikic et al, 2012). Quinoa has strong antioxidant activity and a high amino acid score in comparison with wheat (Watanabe et al, 2003;Asao and Watanabe, 2010). It is proposed that the addition of quinoa flour may raise the antioxidant capacity and amino acid score in substituted food.…”

“…Also, it has a high content of minerals, such as calcium, magnesium, iron and potassium, compared with other cereals (Galvez et al, 2010). In recent years, the functional properties of food have been of increasing interest, and the functional properties of quinoa, such as its suppressive effect on increased blood pressure (Ogawa et al, 2001), serum and liver cholesterol-lowering effects (Takao et al, 2005), antioxidant activity and allergenicity (Asao and Watanabe, 2010), have been investigated.Oxidation of oils and fats contained in food during storage produces a complex mixture of volatiles that significantly affect the sensory properties of food, resulting in reduced nutritional quality, as well as harmful effects on human health. Quinoa flour can be used as a substitute for wheat flour in the production of food.…”