Al-Farsi Mohamed, Alasalvar Cesarettin, Morris Anne, Baron Mark, Shahidi Fereidoon
Plant Research Center, Ministry of Agriculture and Fisheries, Al-Khoud, Muscat, Oman.
J Agric Food Chem. 2005 Sep 21;53(19):7592-9. doi: 10.1021/jf050579q.
Fresh and sun-dried dates of three native varieties from Oman, namely, Fard, Khasab, and Khalas, were examined for their antioxidant activity and total contents of anthocyanins, carotenoids, and phenolics, as well as free and bound phenolic acids. All results are expressed as mean value +/- standard deviation (n = 3) on a fresh weight basis. Fresh date varieties were found to be a good source of antioxidants (11687-20604 micromol of Trolox equiv/g), total contents of anthocyanins (0.24-1.52 mg of cyanidin 3-glucoside equiv/100 g), carotenoids (1.31-3.03 mg/100 g), phenolics (134-280 mg of ferulic acid equiv/100 g), free phenolic acids (2.61-12.27 mg/100 g), and bound phenolic acids (6.84-30.25 mg/100 g). A significant (p < 0.05) amount of antioxidants and carotenoids was lost after sun-drying of dates, whereas the total content of phenolics and free and bound phenolic acids increased significantly (p < 0.05). Anthocyanins were detected only in fresh dates. Date varieties had different levels and patterns of phenolic acids. Four free phenolic acids (protocatechuic acid, vanillic acid, syringic acid, and ferulic acid) and nine bound phenolic acids (gallic acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, syringic acid, p-coumaric acid, ferulic acid, and o-coumaric acid) were tentatively identified. Of the date varieties studied, Khalas, which is considered to be premium quality, had higher antioxidant activity, total carotenoids, and bound phenolic acids than other varieties. These results suggest that all date varieties serve as a good source of natural antioxidants and could potentially be considered as a functional food or functional food ingredient, although some of their antioxidant constituents are lost during sun-drying.
对来自阿曼的三个本地品种的新鲜枣和晒干枣进行了检测，这三个品种分别是法德枣（Fard）、哈萨布枣（Khasab）和哈利斯枣（Khalas），检测内容包括它们的抗氧化活性、花青素、类胡萝卜素和酚类物质的总含量，以及游离酚酸和结合酚酸。所有结果均以鲜重为基础表示为平均值±标准差（n = 3）。发现新鲜枣品种是抗氧化剂的良好来源（11687 - 20604微摩尔Trolox当量/克）、花青素总含量（0.24 - 1.52毫克矢车菊素3 - 葡萄糖苷当量/100克）、类胡萝卜素（1.31 - 3.03毫克/100克）、酚类物质（134 - 280毫克阿魏酸当量/100克）、游离酚酸（2.61 - 12.27毫克/100克）和结合酚酸（6.84 - 30.25毫克/100克）。枣晒干后，大量（p < 0.05）的抗氧化剂和类胡萝卜素损失，而酚类物质以及游离和结合酚酸的总含量显著增加（p < 0.05）。花青素仅在新鲜枣中被检测到。枣品种的酚酸水平和模式各不相同。初步鉴定出四种游离酚酸（原儿茶酸、香草酸、丁香酸和阿魏酸）和九种结合酚酸（没食子酸、原儿茶酸、对羟基苯甲酸、香草酸、咖啡酸、丁香酸、对香豆酸、阿魏酸和邻香豆酸）。在所研究的枣品种中，被认为是优质品种的哈利斯枣比其他品种具有更高的抗氧化活性、总类胡萝卜素和结合酚酸。这些结果表明，所有枣品种都是天然抗氧化剂的良好来源，尽管它们的一些抗氧化成分在晒干过程中会损失，但仍有可能被视为功能性食品或功能性食品成分。
