PDF(Pubmed)
Abstract：
This study explores the potential of olive leaves, long integral to Mediterranean traditional medicine, as a rich source of valuable compounds. The challenge lies in their considerable water content, hindering these compounds\' full valorization. Four drying methods (air-drying, oven-drying, freeze-drying and solar-drying) were investigated for their impact on nutrient and bioactive compound content in the leaves of four olive varieties (\"Arbequina\", \"Koroneiki\", \"Menara\" and \"Picholine Marocaine\") cultivated in Morocco. In their fresh state, \"Picholine Marocaine\" exhibited the highest protein levels (6.11%), \"Arbequina\" had the highest phenolic content (20.18 mg gallic acid equivalents/g fresh weight (FW)), and \"Koroneiki\" and \"Menara\" were highest in flavonoids (3.28 mg quercetin equivalents/g FW). Specific drying methods proved optimal for different varieties. Oven-drying at 60 °C and 70 °C effectively preserved protein, while phenolic content varied with drying conditions. Air-drying and freeze-drying demonstrated effectiveness for flavonoids. In addition, an analytical approach using high-performance liquid chromatography and diode array detection (HPLC-DAD) was applied to investigate the effects of the different drying methods on the bioactive fraction of the analyzed samples. The results showed qualitative and quantitative differences depending on both the variety and the drying method used. A total of 11 phenolic compounds were tentatively identified, with oleuropein being the most abundant in all the samples analyzed. The freeze-dried samples showed the highest content of oleuropein in the varieties \"Arbequina\" and \"Picholine Marocaine\" compared to the other methods analyzed. In contrast, \"Koroneiki\" and \"Menara\" had higher oleuropein content when air dried. Overall, the obtained results highlight the importance of tailored drying techniques for the preservation of nutrients and bioactive compounds in olive leaves.
摘要：
这项研究探索了橄榄叶的潜力，地中海传统医学的长期组成部分，作为有价值的化合物的丰富来源。挑战在于它们的含水量相当大，阻碍这些化合物的完全价值化。四种干燥方法(空气干燥，烤箱干燥，研究了冷冻干燥和太阳能干燥）对四种橄榄品种（“Arbequina”，\"Koroneiki\",“Menara”和“PicholineMarocaine”）在摩洛哥种植。在他们新鲜的状态下，“PicholineMarocaine”显示出最高的蛋白质水平（6.11％），“Arbequina”的酚类含量最高（20.18mg没食子酸当量/g鲜重（FW）），“Koroneiki”和“Menara”的类黄酮含量最高（3.28mg槲皮素当量/gFW）。特定的干燥方法被证明是不同品种的最佳选择。60°C和70°C的烘箱干燥可有效保存蛋白质，而酚含量随干燥条件而变化。空气干燥和冷冻干燥证明了类黄酮的有效性。此外,采用高效液相色谱和二极管阵列检测(HPLC-DAD)的分析方法研究了不同干燥方法对分析样品生物活性组分的影响.结果表明，定性和定量差异取决于品种和使用的干燥方法。总共初步鉴定了11种酚类化合物，在所有分析的样品中，橄榄苦苷是最丰富的。与其他分析方法相比，冻干样品在“Arbequina”和“PicholineMarocaine”品种中的橄榄苦苷含量最高。相比之下,风干时，“Koroneiki”和“Menara”的橄榄苦苷含量较高。总的来说,获得的结果强调了定制干燥技术对保存橄榄叶中营养和生物活性化合物的重要性。
