Laboratory of Food Chemistry and Technology, School of Chemical Engineering, National Technical University of Athens, 5 Iroon Polytechniou St., 15780 Zografou, Greece.
Molecules. 2023 Jan 1;28(1):353. doi: 10.3390/molecules28010353.
Natural deep eutectic solvents (NADES) composed of choline chloride with maltose (CMA), glycerol (CGL), citric (CCA) and lactic acid (CLA) combined with microwave (MAE), ultrasound (UAE), homogenate (HAE) and high hydrostatic pressure (HHPAE)-assisted extraction methods were applied to recover and compare olive leaf phenolic compounds. The resultant extracts were evaluated for their total phenol content (TPC), phenolic profile and antioxidant activity and compared with those of water and ethanol:water 70% / extracts. HAE was proven to be the most efficient method for the recovery of olive leaf phenolic compounds. The highest TPC (55.12 ± 1.08 mg GAE/g d.w.) was found in CCA extracts after HAE at 60 °C and 12,000 rpm, and the maximum antioxidant activity (3.32 ± 0.39 g d.w./g DPPH) was found in CGL extracts after UAE at 60 °C for 30 min. The TPCs of ethanol extracts were found to be higher than those of NADES extracts in most cases. The predominant phenolic compounds in the extracts were oleuropein, hydrohytyrosol and rutin.
天然深共晶溶剂 (NADES) 由氯化胆碱与麦芽糖 (CMA)、甘油 (CGL)、柠檬酸 (CCA) 和乳酸 (CLA) 组成，结合微波 (MAE)、超声 (UAE)、匀浆 (HAE) 和高静压 (HHPAE) 辅助提取方法，用于回收和比较橄榄叶酚类化合物。评估了所得提取物的总酚含量 (TPC)、酚类图谱和抗氧化活性，并与水和乙醇：水 70%/提取物进行了比较。HAE 被证明是回收橄榄叶酚类化合物最有效的方法。在 60°C 和 12,000 rpm 下通过 HAE 从 CCA 提取物中获得最高的 TPC（55.12 ± 1.08 mg GAE/g d.w.），在 60°C 下通过 UAE 30 分钟从 CGL 提取物中获得最大的抗氧化活性（3.32 ± 0.39 g d.w./g DPPH）。在大多数情况下，乙醇提取物的 TPC 高于 NADES 提取物。提取物中的主要酚类化合物是橄榄苦苷、羟基酪醇和芦丁。
