Laboratory of Food Chemistry and Technology, School of Chemical Engineering, National Technical University of Athens, 5 Heroon Polytechniou Str., 15780 Athens, Greece.
Molecules. 2024 May 14;29(10):2303. doi: 10.3390/molecules29102303.
Olive oil production is characterized by large amounts of waste, and yet is considerably highly valued. Olive pomace can serve as a cheap source of bioactive compounds (BACs) with important antioxidant activity. Novel technologies like Pulsed Electric Fields (PEF) and High Pressure (HP) and microwave (MW) processing are considered green alternatives for the recovery of BACs. Different microwave (150-600 W), PEF (1-5 kV/cm field strength, 100-1500 pulses/15 µs width), and HP (250-650 MPa) conditions, in various product/solvent ratios, methanol concentrations, extraction temperatures, and processing times were investigated. Results indicated that the optimal MW extraction conditions were 300 W at 50 °C for 5 min using 60% / methanol with a product/solvent ratio of 1:10 g/mL. Similarly, the mix of 40% / methanol with olive pomace, treated at 650 MPa for the time needed for pressure build-up (1 min) were considered as optimal extraction conditions in the case of HP, while for PEF the optimal conditions were 60% / methanol with a product/solvent ratio of 1:10 g/mL, treated at 5000 pulses, followed by 1 h extraction under stirring conditions. Therefore, these alternative extraction technologies could assist the conventional practice in minimizing waste production and simultaneously align with the requirements of the circular bioeconomy concept.
橄榄油生产的特点是产生大量的废物，但却具有相当高的价值。橄榄渣可以作为生物活性化合物（BAC）的廉价来源，具有重要的抗氧化活性。脉冲电场（PEF）、高压（HP）和微波（MW）等新技术被认为是回收 BAC 的绿色替代方法。不同的微波（150-600 W）、PEF（1-5 kV/cm 场强，100-1500 个脉冲/15 µs 宽度）和 HP（250-650 MPa）条件，在不同的产品/溶剂比、甲醇浓度、提取温度和处理时间下进行了研究。结果表明，MW 最佳提取条件为 300 W、50 °C、5 min，使用 60%甲醇，产品/溶剂比为 1:10 g/mL。同样，将 40%甲醇与橄榄渣混合，在 650 MPa 下处理到建立压力所需的时间（1 分钟）被认为是 HP 情况下的最佳提取条件，而对于 PEF，最佳条件是 60%甲醇，产品/溶剂比为 1:10 g/mL，处理 5000 个脉冲，然后在搅拌条件下提取 1 小时。因此，这些替代提取技术可以帮助常规实践减少废物的产生，同时符合循环生物经济概念的要求。
