Institute of Crop Science, Chinese Academy of Agricultural Sciences, No 80 South Xueyuan Road, Haidian District, Beijing 100081, People's Republic of China.
J Agric Food Chem. 2010 Jan 27;58(2):770-4. doi: 10.1021/jf903234c.
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 alpha-glucosidase inhibitory activity, and (iii) correlate the TPC with total antioxidant activity and alpha-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 alpha-glucosidase inhibitory activity. A significant positive correlation of the antioxidant activity and alpha-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 alpha-glucosidase inhibitory among all of the colored grains tested and can be further explored as a functional food.
有色谷物包括红米、紫米、黑米、紫玉米和黑豆，它们都含有花青素。本研究旨在：（i）鉴定和定量分析各种花青素，并测定总酚含量（TPC）；（ii）评估抗氧化和α-葡萄糖苷酶抑制活性；（iii）将 TPC 与这些有色谷物的总抗氧化活性和α-葡萄糖苷酶抑制能力相关联。TPC 采用福林-酚试剂比色法测定，而总抗氧化活性则通过基于 1,1-二苯基-2-苦基肼（DPPH）自由基清除活性的方法来测定。在所研究的有色谷物中，黑米的 TPC 最高，是红米的 86 倍。此外，黑米的总花青素含量和α-葡萄糖苷酶抑制活性最高。本研究观察到抗氧化活性和α-葡萄糖苷酶抑制活性与总花青素含量和 TPC 之间存在显著的正相关关系。研究结果表明，黑米具有所有测试的有色谷物中最高的抗氧化活性和α-葡萄糖苷酶抑制活性，可进一步作为功能性食品进行探索。
