Functional and Bioactive Properties of Quinoa and Amaranth

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.