Farag Mohamed A, Mohsen Mahmoud, Heinke Ramona, Wessjohann Ludger A
Pharmacognosy Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt; Leibniz Institute of Plant Biochemistry, Dept. Bioorganic Chemistry, Weinberg 3, D-06120 Halle (Saale), Germany.
Pharmacognosy Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
Food Res Int. 2014 Oct;64:218-226. doi: 10.1016/j.foodres.2014.06.021. Epub 2014 Jun 20.
Date palm fruits of the species Phoenix dactylifera exhibit a great diversity in sensory attributes including skin color, smell and taste. This study attempts to elucidate the primary and secondary metabolite profiles of 21 date varieties from Egypt. A major difficulty is sugar rich matrix and skin-fibers embedding the secondary metabolites. A total of 49 metabolites extracted from the fruit skin were evaluated in a UPLC/PDA/ESI-qTOF-MS based metabolomics study. The total phenolic contents of the varieties varied from 233 to 1897mg/100g (2.3-19g/kg) dry weight. The predominant flavones were glycosides of luteolin and apigenin, quercetin conjugates were the principal flavonols, whereas caffeoyl shikimic acid was the main hydroxycinnamic acid conjugate. Aside from these major phenolic classes, a group of sphingolipids, fatty and other organic acids was also identified. The total non-fatty organic acid content correlates with reported shelf lives. GC-MS was further utilized to localize primary metabolites in fruits (i.e. sugars and organic acids) with glucose and fructose accounting for up to 95% of TIC among most varieties. Principal component and clustering analyses reveal that flavonols and sugars, both contribute the most to variety classification. This study provides the most complete map for polyphenol & sugar distribution in Egyptian date fruit varieties. By describing the metabolite profiles in a diverse dataset of P. dactylifera, this study provides the basis for future investigations of date fruit nutritional value beyond providing energy and its potential for nutraceutical enhancement or storability.
海枣属植物海枣的果实，在感官特性方面呈现出极大的多样性，包括果皮颜色、气味和味道。本研究旨在阐明来自埃及的21个枣品种的初级和次级代谢产物谱。一个主要困难在于富含糖分的基质以及包裹着次级代谢产物的果皮纤维。在一项基于超高效液相色谱/光电二极管阵列/电喷雾电离-四极杆飞行时间质谱的代谢组学研究中，对从果实表皮提取的总共49种代谢产物进行了评估。这些品种的总酚含量在233至1897毫克/100克（2.3 - 19克/千克）干重之间变化。主要的黄酮类化合物是木犀草素和芹菜素的糖苷，槲皮素共轭物是主要的黄酮醇类，而咖啡酰莽草酸是主要的羟基肉桂酸共轭物。除了这些主要的酚类物质外，还鉴定出了一组鞘脂类、脂肪酸和其他有机酸。总非脂肪酸有机酸含量与报道的货架期相关。气相色谱-质谱联用技术进一步用于确定果实中的初级代谢产物（即糖和有机酸）的位置，在大多数品种中，葡萄糖和果糖占总离子流的比例高达95%。主成分分析和聚类分析表明，黄酮醇类和糖类对品种分类的贡献最大。本研究提供了埃及枣果品种中多酚和糖分分布的最完整图谱。通过描述海枣不同数据集中的代谢产物谱，本研究为未来枣果营养价值的研究提供了基础，除了提供能量外，还涉及枣果在营养强化或储存方面的潜力。
