Relationship between antioxidation and grain colors of wheat (Triticum aestivum L.)

Chinese. 以抗活性氧活力单位、抗超氧阴离子活力单位和总抗氧化活力单位为指标，研究了白、红、紫、深紫、紫黑、蓝等不同颜色小麦籽粒的抗氧化能力，并分析了其与色素、黄酮等抗氧化物质含量和抗氧化酶活性之间的关系。结果表明，小麦籽粒颜色与其抗氧化活性之间存在着非常密切的关系，蓝、紫黑、深紫、紫等黑粒小麦籽粒的抗氧化能力高于白粒和红粒小麦。黑粒小麦的总黄酮、氨基酸、Vc、类胡萝卜素等抗氧化物质含量和SOD等抗氧化酶活性高于普通白粒和红粒小麦；并且籽粒色素含量、总黄酮含量、总氨基酸含量以及SOD活性与3个抗氧化能力指标显著或极显著正相关，Vc和类胡萝卜素含量与3个抗氧化指标之一或之二显著或极显著正相关，说明色素、黄酮、SOD、Vc和氨基酸等是蓝、紫黑、深紫、紫等黑粒小麦的抗氧化能力强于白粒和红粒小麦的主要物质基础。

English. Grains with black color are considered benefit to human＇s health. Several cultivars or lines of wheat with black grain have been successfully bred in China. The antioxidation capacities of wheat grains with different colors were characterized by using active oxygen resistance reactivity units （AORRU）, superoxide anion resistance reactivity units （SARRU） and total antioxidant reactivity units （TARU） as antioxidation indices. The relationships between antioxidation indices of wheat grains and the corresponding concentrations of pigments and flavonoid compounds as well as antioxidant enzyme activities were also investigated. The results indicated that blue, black purple, dark purple and purple wheat grains were significantly higher in the levels of AORRU, SARRU and TARU than white and red wheat grains. Their concentrations of antioxidants such as total flavonoids, amino acids, vitamin C and carotenoids, and activities of antioxidases such as superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） were also higher than common white or red wheat grains. Grain pigment content, total flavonoid content, total amino acid content and SOD activity showed significant positive correlations to the three antioxidation indices at P ≤ 0.05 or P ≤0.01, while vitamin C content! and carotenoid content showed significant positive correlations to one or two of the three indices at P≤0.05 or P≤0.01. It was concluded that the pigments, flavonoids, SOD, vitamin C and amino acids are the main substances those confer distinguished antioxidation capacities of blue, purple black, dark purple and purple wheat grains as compared with common white and red wheat grains.