The total polyphenols and the antioxidant potentials of some selected cereals and pseudocereals

The objective of the present study was to investigate the effect of phenolic substances and proteins on the antioxidant potentials in some cereals and pseudocereals and to compare their bioability. The polyphenol dry matter extracts (PDME) from the investigated seeds of buckwheat, rice, soybean, amaranth and quinoa with 1.2 M HCl in 50% methanol/water (PDME50%Met/HCl) exhibited higher inhibition of lipid peroxidation than the ones extracted with 50% methanol/water (PDME50%Met) and were comparable to the antioxidant activity of butylated hydroxyanisole at concentration of 0.2 mg mL−1. The antioxidant activities of these seed extracts determined by 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonate)-ABTS•+/K2S2O8, βcarotene bleaching (β-carotene), and 1,1-diphenyl-2picrylhydrazyl (DPPH) radical scavenging methods showed high correlation coefficients (R2) such as 0.9515, 0.9058 and 0.8723, respectively, with the presence of total polyphenols estimated by Folin-Ciocalteu assay. These results indicate that the major antioxidant components in these extracts mostly derived from the polyphenols, and proteins showed S. Gorinstein ( ) · E. Katrich Department of Medicinal Chemistry and Natural Products, School of Pharmacy, The Hebrew University-Hadassah Medical School, P.O. Box 12065, Jerusalem, 91120, Israel e-mail: [email protected] Tel.: +972-2-6758690 Fax: +972-2-6757076 O. J. M. Vargas Department of Food Chemistry, Universidad Pedagógica y Tecnológica de Colombia, Tunja, Colombia N. O. Jaramillo Facultad de Ciencias Exactas y Naturales, Instituto de Biologia, Universidad de Antioquia, Medellin, Colombia I. A. Salas Centro de Investigacion de Bioquimica y Nutricion, Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Peru A. L. M. Ayala Departamento de Biotecnologia, Centro de Desarrollo de Productos Bioticos, Instituto Politecnico Nacional, Morelos, Mexico P. Arancibia-Avila · F. Toledo Department of Basic Sciences, Universidad del Bio-Bio, Chillan, Chile S. Trakhtenberg Kaplan University Medical Center, Rehovot, Israel only minimal values of bioactivity. Based on high contents of polyphenols, anthocyanins, flavonoids and their antioxidant activities pseudocereals such as buckwheat, quinoa and amaranth can be a substitute for cereals for common and atherosclerotic diets and sometimes in the allergic cases.