Masuda Akiko, Hidaka Kayo, Honda Sari, Taniguchi Asami, Doi Sayaka, Masuda Toshiya
Faculty of Human Life Science, Shikoku University.
Graduate School of Human Life Science, Osaka City University.
J Nutr Sci Vitaminol (Tokyo). 2018;64(6):466-472. doi: 10.3177/jnsv.64.466.
The radical scavenging activity of commercially available roasted (deep colored) and unroasted (light colored) egoma (Perilla frutescens var. frutescens) oils was evaluated by the DPPH radical scavenging method. The antiradical activity of roasted oils was higher than that of unroasted oils, and the activity of methanol-water extracts from the roasted egoma oils was significantly higher than that of unroasted oils. The antiradical activity of the methanol-water fractions was strongly correlated to that of whole oils (r=0.72) and the color depth of oils (r=0.93), which was an index of roasting. Fractionation of the methanol-water extract of a roasted egoma oil according to molecular size using ultra membrane filters revealed that the fraction under 3 kDa had the strongest radical scavenging activity. Subsequent preparative HPLC separation using an ODS column also revealed that the second fraction was the most active. Our HPLC analytical method for DPPH radical scavengers in complex mixtures detected four strong radical scavenger peaks in the fraction. Among the detected peaks, two peaks were determined to be derived from rosmarinic acid and luteolin by comparison with the retention times and UV spectra of the authentic samples, and the other two compounds could not be identified because no characteristic UV spectra were observed. These identified polyphenols (rosmarinic acid and luteolin) have been reported to be present in the non-oily part of egoma seeds. They probably migrated to the oily part during the egoma oil roasting process.
采用DPPH自由基清除法对市售烘焙（深色）和未烘焙（浅色）紫苏油的自由基清除活性进行了评价。烘焙油的抗自由基活性高于未烘焙油，且烘焙紫苏油的甲醇 - 水提取物的活性显著高于未烘焙油。甲醇 - 水馏分的抗自由基活性与全油的抗自由基活性（r = 0.72）和油的颜色深度（r = 0.93，作为烘焙指标）密切相关。使用超滤膜过滤器根据分子大小对烘焙紫苏油的甲醇 - 水提取物进行分级分离，结果表明分子量小于3 kDa的馏分具有最强的自由基清除活性。随后使用ODS柱进行制备型HPLC分离，结果还表明第二馏分活性最高。我们用于检测复杂混合物中DPPH自由基清除剂的HPLC分析方法在该馏分中检测到四个强自由基清除剂峰。在检测到的峰中，通过与标准样品的保留时间和紫外光谱进行比较，确定其中两个峰源自迷迭香酸和木犀草素，另外两种化合物由于未观察到特征紫外光谱而无法鉴定。这些已鉴定的多酚（迷迭香酸和木犀草素）据报道存在于紫苏籽的非油性部分。它们可能在紫苏油烘焙过程中迁移到了油性部分。
