Antioxidant and α-Glucosidase Inhibitory Activity of Colored Grains in China

• Published in: Journal of agricultural and food chemistry Vol. 58; no. 2; pp. 770 - 774
• Main Authors: Yao, Yang, Sang, Wei, Zhou, Mengjie, Ren, Guixing
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 27.01.2010
• Subjects: alpha-glucosidase; alpha-Glucosidases - analysis; Analytical Methods; anthocyanins; Anthocyanins - analysis; antioxidant activity; Antioxidants - analysis; Biological and medical sciences; black rice; Cereal and baking product industries; China; color; colored grains; Edible Grain - chemistry; enzyme activity; Enzyme Inhibitors - analysis; food analysis; food composition; Food industries; functional foods; Fundamental and applied biological sciences. Psychology; Glycoside Hydrolase Inhibitors; grain products; phenolic compounds; Phenols - analysis; Pigmentation; plant pigments; Plant Proteins - analysis; Plant Proteins - antagonists & inhibitors; China; Asia; Anthocyanins; antioxidant; α-glucosidase inhibitory; Anthocyanin; Enzyme; Color; Antioxidant; Flavonoid; Glycosylases; Polyphenol; α-Glucosidase; Glycosidases; Pigments; Hydrolases; Cereal
• DOI: 10.1021/jf903234c
• ISSN: 0021-8561; 1520-5118

Colored grains including red, purple, and black rice, purple corn, black barley, and black soybean contain anthocyanins. The present study was designed to (i) identify and quantify the individual anthocyanins and measure the total phenolic content (TPC), (ii) evaluate the antioxidant and α-glucosidase inhibitory activity, and (iii) correlate the TPC with total antioxidant activity and α-glucosidase inhibitory potency in these colored grains. The TPC was measured using a Folin−Ciocalteu assay, while the total antioxidant activity was determined by a method based on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity. Among all of the studied colored grains, black rice possessed the highest TPC, which was 86 times greater than that of red rice. In addition, black rice had the highest total anthocyanin contents and α-glucosidase inhibitory activity. A significant positive correlation of the antioxidant activity and α-glucosidase inhibitory activity with total anthocyanin content and TPC was observed in this study. It is concluded that black rice possesses the highest antioxidant activity and α-glucosidase inhibitory among all of the colored grains tested and can be further explored as a functional food.