Huamán-Castilla Nils Leander, Mamani Apaza Luis Omar, Zirena Vilca Franz, Saldaña Erick, Diaz-Valencia Yemina Karen, Mariotti-Celis María Salomé
Escuela Profesional de Ingeniería Agroindustrial, Universidad Nacional de Moquegua, Prolongación Calle Ancash s/n, Moquegua 18001, Peru.
Laboratorio de Tecnologías Sustentables para la Extracción de Compuestos de Alto Valor, Instituto de Investigación para el Desarrollo del Perú (IINDEP), Universidad Nacional de Moquegua, Moquegua 18001, Peru.
Antioxidants (Basel). 2024 Dec 12;13(12):1523. doi: 10.3390/antiox13121523.
Olive leaves are agro-industrial waste that pose an environmental management problem. However, they contain polyphenolic compounds with important bioactive properties beneficial to human. This study aimed to evaluate the effectiveness of two extraction technologies (pressurized liquid extraction and ultrasound-assisted extraction) combined with green solvents (pure water, 15% ethanol, and 15% glycerol) at 50 °C and 70 °C. The goal was to obtain extracts with both antioxidant capacity and antihyperglycemic properties from olive leaves. Pressurized liquid extraction with 15% glycerol at 70 °C was the most effective method for obtaining extracts rich in total polyphenols (19.46 mg GAE/g dw), with an antioxidant capacity of 4.11 mg/mL (inhibition capacity: IC50) and 500.26 µmol TE/g dw. For both extraction methods at 70 °C, glycerol was more effective at recovering phenolic acids, stilbenes and secoiridoid; while ethanol was more effective for recovering flavonols and phenylethanoids. Oleuropein was the most important polyphenol extracted from both pressurized liquid and ultrasound-assisted extractions, with concentrations of 171.48 µg/g dw and 246.70 µg/g dw, respectively. The extract obtained from pressurized liquid extraction with 15% ethanol at 70 °C exhibited significant inhibition (70%) of α-glucosidase enzymes, similar to the reference drug acarbose. In contrast, these extracts showed low inhibitory activity against the α-amylase enzyme. These findings can be applied to the development of functional foods and nutraceutical supplements aimed at managing postprandial glycemic response, offering a natural alternative for supporting type 2 diabetes management.
橄榄叶是农业工业废弃物，会带来环境管理问题。然而，它们含有对人体有益的具有重要生物活性的多酚类化合物。本研究旨在评估两种提取技术（加压液体萃取和超声辅助萃取）与绿色溶剂（纯水、15%乙醇和15%甘油）在50℃和70℃下的有效性。目标是从橄榄叶中获得具有抗氧化能力和降血糖特性的提取物。在70℃下用15%甘油进行加压液体萃取是获得富含总多酚（19.46毫克没食子酸当量/克干重）提取物的最有效方法，其抗氧化能力为4.11毫克/毫升（抑制能力：IC50），总抗氧化能力为500.26微摩尔TE/克干重。对于70℃下的两种萃取方法，甘油在回收酚酸、芪类和裂环环烯醚萜方面更有效；而乙醇在回收黄酮醇和苯乙醇类方面更有效。橄榄苦苷是从加压液体萃取和超声辅助萃取中提取的最重要的多酚，浓度分别为171.48微克/克干重和246.70微克/克干重。在70℃下用15%乙醇进行加压液体萃取得到的提取物对α-葡萄糖苷酶表现出显著抑制作用（70%），与参考药物阿卡波糖相似。相比之下，这些提取物对α-淀粉酶的抑制活性较低。这些发现可应用于开发旨在控制餐后血糖反应的功能性食品和营养补充剂，为支持2型糖尿病管理提供一种天然替代品。
