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...