日喀则市青稞全籽粒抗氧化品质研究

为揭示日喀则青稞全籽粒所含酚类物质与抗氧化能力间的关系,遴选出抗氧化品质优异的品种,对13份青稞材料的酚类物质含量和抗氧化能力进行了品种间的多重比较分析、酚类物质含量和抗氧化能力的相关分析、抗氧化品质的主成分分析以及品种间的聚类分析。结果表明,按籽粒颜色可将13份青稞品种划分为棕、紫、黑三色,深色(紫色和黑色)品种中花色苷、原花青素、总黄酮和总酚含量较高,且氧化自由基吸收能力(ORAC)、铁离子还原能力(FRAP)、1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除能力也高于浅色(棕色)品种。ORAC、FRAP、DPPH自由基清除能力与酚类物质含量之间存在显著或极显著相关性,而金属离子螯合能力(MCC)与酚类物质无显著相关性。主成分分析和聚类分析结果表明,可通过籽粒颜色来进行青稞抗氧化品质初筛,深色青稞品种尤其是黑色青稞品种籽粒抗氧化品质最高。研究青稞籽粒酚类物质抗氧化有助于完善青稞抗氧化品质评价体系,为开发青稞抗氧化功能食品筛选出抗氧化能力优异的品种。

Antioxidant Capacity of Highland Barley in Shigatse

In order to develop functional food using highland barley in Shigatse, multiple comparisons were conducted between the phenolic substances and their antioxidant capacity. Correlation analysis(PCA) of phenolic content and antioxidant capacity, principal component analysis(PCA) of antioxidant quality, and cluster analysis among 13 species were also applied. 13 varieties were separated by the color, i.e., brown, purple, and black categories. The content of anthocyanin, procyanidin, total flavonoids, and total phenolics in purple and black varieties was higher than that of the brown ones. Similarly, the oxygen radical absorption capacity (ORAC), ferric ion reducing antioxidant power (FRAP), and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) of dark varieties were also higher than that of the light ones. There were significant correlations among ORAC, FRAP, DPPH and phenol content. But the metal ion chelating capacity (MCC) was independent of the classified substances. The results of PCA and cluster analysis both indicated that screening the highland barley through grain color was feasible. Dark highland barley variety, especially the black ones, showed higher antioxidant ability, which was suitable for the development of antioxidant functional food. This study on the phenol substances within barley grains is helpful to improve the evaluation system of antioxidant quality and to screen varieties with excellent antioxidant propeties.