Department of Biochemistry, Memorial University of Newfoundland, St John's, NL, Canada.
J Agric Food Chem. 2010 Jun 9;58(11):6706-14. doi: 10.1021/jf100868b.
Soluble and insoluble-bound phenolic extracts of several varieties of millet (kodo, finger, foxtail, proso, pearl, and little millets) whole grains were evaluated for their phenolic contents and antioxidative efficacy using trolox equivalent antioxidant capacity (TEAC), reducing power (RP), and beta-carotene-linoleate model system as well as ferrous chelating activity. In addition, ferulic and p-coumaric acids were present in soluble and bound phenolic fractions of millets, and their contents were determined using high-performance liquid chromatography (HPLC) and HPLC-mass spectrometry (MS). Kodo millet had the highest total phenolic content, whereas proso millet possessed the least. All millet varieties showed high antioxidant activities, although the order of their efficacy was assay dependent. HPLC analysis of millet phenolic extracts demonstrated that the bound fractions contained more ferulic and p-coumaric acids compared to their soluble counterparts. The results of this study showed that soluble as well as bound fractions of millet grains are rich sources of phenolic compounds with antioxidant, metal chelating, and reducing power. The potential of whole millets as natural sources of antioxidants depends on the variety used. The importance of the insoluble bound fraction of millet as a source of ferulic acid and p-coumaric acid was established, and their contribution to the total phenolic content must be taken into account in the assessment of the antioxidant activity of millets.
几种小米（黑穗、手指、黍、黍、珍珠和小米）全谷物的可溶和不可溶结合的酚类提取物的酚类含量和抗氧化功效进行了评估，使用 Trolox 当量抗氧化能力 (TEAC)、还原能力 (RP) 和β-胡萝卜素-亚油酸模型系统以及亚铁螯合活性。此外，小米中的可溶和结合酚类部分存在阿魏酸和对香豆酸，并用高效液相色谱法 (HPLC) 和 HPLC-质谱法 (MS) 测定其含量。黑穗小米的总酚含量最高，而黍的总酚含量最低。所有小米品种均表现出较高的抗氧化活性，尽管其功效顺序取决于测定方法。小米酚类提取物的 HPLC 分析表明，与可溶部分相比，结合部分含有更多的阿魏酸和对香豆酸。本研究结果表明，小米颗粒的可溶和不可溶结合部分均是富含酚类化合物的抗氧化剂、金属螯合剂和还原能力的良好来源。全小米作为天然抗氧化剂来源的潜力取决于所用的品种。确定了小米中不可溶结合部分作为阿魏酸和对香豆酸来源的重要性，在评估小米的抗氧化活性时，必须考虑其对总酚含量的贡献。
