Preparation of hypoglycemic anthocyanins from mulberry (Fructus mori) fruits by ultrahigh pressure extraction

In this study, mulberry anthocyanins were extracted by ultrahigh pressure extraction (UPE) and investigated on biological activities. Based on response surface methodology (RSM), the optimum conditions were 430 MPa of extraction pressure, 75% v/v ethanol concentration, 12:1 v/w liquid-solid ratio, the highest extraction yield was 1.97 ± 0.11 mg/g. Six anthocyanins were identified by ultrahigh performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS^E). The antioxidant activity of anthocyanins was determined by reducing powder, the scavenging of hydroxyl radical and 2,2-diphenyl−1-picrylhydrazyl (DPPH) free radical activity. In addition, the α-glucosidase and α-amylase inhibitory rate of mulberry anthocyanins rose in a dose-dependence manner. When anthocyanin concentration is 0.50 mg/mL, the highest inhibition percentage is 65.51% and 81.72%, respectively. The high temperature, high pH and outdoor light will affect the inhibitory ability of enzyme. These findings could provide optimal extraction methods and provide perspective for mulberries anthocyanins using in functional food.     

An efficient approach for the extraction of anthocyanins from Lycium ruthenicum using semi-continuous liquid phase pulsed electrical discharge system

Lycium ruthenicum is regarded as a good source of natural anthocyanins. In this work, we proposed a novel semi-continuous liquid-phase pulsed discharge (LPD) system for the extraction of anthocyanins from Lycium ruthenicum. The optimized conditions for this method were: 20% ethanol concentration, 7 pH value, 8 kV input voltage, 27 mL/min volume flow, and 8 min treatment time. Under these conditions, a maximum anthocyanins recovery rate (95.69%) was obtained. Compared with batch LPD and heat-assisted extraction (HAE), semi-continuous LPD showed higher anthocyanins yield, shorter time, and lower energy consumption. The antioxidant activity of extracts was determined by scavenging ability of DPPH and ABTS radicals and, reducing ability of Fe³⁺. The results indicated that the antioxidant activity of batch LPD, HAE, and semi-continuous LPD were similar. Besides, the HPLC chromatograms showed that three methods had similar anthocyanins composition. Thus, semi-continuous LPD was an good and promising method for the extraction of natural anthocyanins.     

Pressurized green liquid extraction of betalains and phenolic compounds from Opuntia stricta var. Dillenii whole fruit: Process optimization and biological activities of green extracts

The Opuntia Stricta var. Dillenii's prickly pears are an underutilized fruits, which provide a great source of betalains (mainly, betacyanins) and phenolic compounds (phenolic acids and flavonoids) that could play an important role in health-promotion. This study focuses on the optimization of process for the green extraction of betalains and phenolic compounds from Opuntia stricta var. Dillenii's whole fruits by Pressurized liquid extraction (PLE), using a response surface methodology (RSM) by a central composite design (CCD) in order to obtain rich extracts in betalains and phenolic compounds with the similar profile of the original one found in O. dillenii fruits (avoiding any degradation of these compounds during the extraction process) with proven biological activities. For PLE optimization, the ethanol volume in water (0–100%, v/v) and the temperature (25–65°C) were selected as independent variables. The identification and quantification of the individual bioactive compounds of the obtained green extracts were done by HPLC-DAD-ESI/MS and HPLC-DAD-ESI/QTOF and their biological activities were determined by in vitro tests, as: the antioxidant activity by the ORAC method and the anti-inflammatory activity by the hyaluronidase inhibition method. Ethanol volume in water (%, v/v) was the variable with most significant (p ≤ 0.05) effect in the target responses (bioactive content and biological activities). The best results were obtained at 50% ethanol in water (v/v) and 25°C temperature (run 10) obtaining extracts with betalains as 2.34 ± 0.18 mg of betanin/g dry weight, 2.51 ± 0.04 mg of 5′´-O-E-sinapoyl-2′-apyosil-phyllocactin/g dry weight, 2.32 ± 0.19 mg of neobetanin/g dry weight and phenolic compounds, 2.08 ± 0.07 mg of piscicid acid/g dry weight and 0.25 ± 0.02 mg of isorhamnetin glucoxyl-rhamnosyl-pentoside (IG2) /g dry weight. The betalain and phenolic profile of the PLE extracts was quite similar to the profile from the conventional extraction, but PLE extraction process enhanced the extraction of some bioactives as neobetanin (39%) andpiscidic acid (124%). All employed PLE process CCD combinations significantly upgrade the in vitro biological activities (antioxidant and anti-inflammatory) of the Opuntia stricta var. Dillenii's PLE green extracts.     

Determination of Anthraquinone Derivatives in Chang-Qing Tea by Using Cloud-Point Extraction and High-Performance Liquid Chromatography

In this paper, a cloud-point extraction method was developed for the determination of five anthraquinone derivatives in Chang-Qing tea by high-performance liquid chromatography. The optimum conditions for micelle extraction were obtained as follows—15% (w/v) Genapol X-080 as extractant, pH 3.5, liquid/solid ratio 80, and extraction time, 40 min. For cloud point preconcentration, 20% (w/v) NaCl was added, and the solution was incubated at 55 °C for 30 min. The detection limits for the five anthraquinone derivatives were in the range of 0.55–3.30 ng ml⁻¹. Average recoveries for the anthraquinone derivatives at three spiked levels were in the range of 84.3–104.1%. Relative standard deviations for six replicate determinations of Chang-Qing tea sample were below 2.39. The established method has been successfully applied to the determination of anthraquinone derivatives in Chang-Qing tea products from three different manufacturers.     

Pressurized liquid extraction as an eco-friendly approach to recover anthocyanin from black rice bran

This study aimed to recover the anthocyanin-rich extract from black rice bran by pressurized liquid extraction (PLE) and compare with the conventional process (heating-stirring extraction - HSE). PLE performs fast and efficiently and results in high yields in less time and less solvent, being considered eco-friendly. The extracts were characterized for thermal and light stabilities, cytotoxicity, antitumoral activity, and cytoprotective effect. Optimum PLE conditions were: 55 °C, a flow rate of 5 mL/min, and solution ethanol:citric acid 0.1 mol/L (50:50, v/v). PLE recovered about 80% of total anthocyanins (2.33 mg/C3GE g), while HSE recovered 46% (1.17 mg/C3GE g). Cyanidin-3-O-glucoside (C3G) was identified (m/z 449) and quantified, 1.63 mg/g for PLE and 1.07 mg/g for HSE. Both anthocyanin-rich extracts in low temperature showed high thermostability, did not present cytotoxicity (normal fibroblast L929 cells), and showed cytoprotection of L929 cells when subjected to oxidative stress with H₂O₂. Overall, the anthocyanin-rich extracts obtained by PLE showed potential to be applied as natural colorants and possibly to improve wound healing.Industrial relevancePLE method is an eco-friendly technology that performs fast and efficient extractions under high temperature and pressure conditions. This study provides information about the extraction of anthocyanin-rich extracts from black rice bran by green PLE process under optimized conditions. The process allowed for obtaining antioxidant-rich extracts with no cytotoxicity and a high potential for application in the food, cosmetic, and biomedical industries.     

Optimising the extraction of tea polyphenols, (−)‐epigallocatechin gallate and theanine from summer green tea by using response surface methodology

In this study, response surface methodology was applied to determine the optimal conditions for the extraction of tea polyphenols, EGCG and theanine from summer green tea. As results, the optimal extraction conditions were determined to be temperature 96 °C, time 40 min and ratio of water to raw material 16 mL g^?1. Under these optimal conditions, the experimental values for tea polyphenols, EGCG, theanine and IC₅₀ for DPPH free radical scavenging activity were 133.41 ± 3.12 mg gallic acid g^?1, 30.23 ± 1.22, 3.99 ± 1.13 mg g^?1 and 724.95 ± 15.12 μg mL^?1, respectively. There was no statistical difference at significant level of 0.05 between the experimental and predicted values. The results suggested that the regression models were accurate and adequate for the bioactives extraction from summer green tea.     

三种茶叶中多酚提取物的抑菌活性及其对致病菌膜渗透性的比较分析

目的:研究3种茶叶中茶多酚的抑菌活性及对菌株细胞膜渗透性的影响。方法:以西湖龙井、铁观音和普洱茶为材料提取茶多酚,以滤纸片法测定茶多酚的抑菌圈直径,二倍肉汤稀释法测定其最小抑菌浓度(MIC)和最小杀菌浓度(MBC),比较其抑菌效果。通过DNA渗透性实验、DNA损伤实验评价茶多酚对细胞膜完整性及对DNA损伤的影响。结果:相同条件下,绿茶(西湖龙井)中茶多酚含量最高为(48.12±3.22) mg/g,青茶(铁观音)次之为(37.36±2.64) mg/g,黑茶(普洱茶)最低为(31.61±1.92) mg/g。绿茶对金黄色葡萄球菌的抑菌作用最强,抑菌圈直径为(1.80±0.06) cm,MIC值为0.125 mg/mL、MBC值为0.25 mg/mL。随着茶多酚提取物浓度的增加,260 nm下的细菌渗透性物质逐渐增多,并且基因组DNA的损伤程度逐渐增大。结论:3种茶叶中绿茶具有更好的抑菌效果,并通过增强细菌细胞膜渗透性,进而对DNA产生一定的损伤。     

紫果西番莲果皮中多酚提取工艺的比较及优化

以紫果西番莲果皮为原料,研究乙醇提取和纤维素酶辅助提取果皮中多酚的最佳工艺条件并对提取效果进行比较。以多酚得率为指标,通过单因素试验考察各个因素对多酚提取效果的影响;采用L₉(34)正交试验优化了纤维素酶辅助提取工艺条件。结果表明,乙醇提取法的最适工艺条件为乙醇体积分数60%,液料比30:1 mL/g,提取时间150 min,浸提温度为40 ℃,多酚得率为(11.648±0.118) mg/g;酶法辅助提取的最佳工艺条件为纤维素酶用量为25 mg/g,液料比为35:1 mL/g,酶解温度40 ℃,酶解时间为60 min,pH=5,多酚得率为(15.096±0.0948) mg/g。比较两种工艺条件下多酚最大得率可知,纤维素酶法辅助提取比乙醇提取法的多酚得率高出29.6%,证明纤维素酶对西番莲果中细胞壁的破碎效果较好,可以提高果皮中多酚的提取得率。     

Quantitative and Qualitative Portrait of Green Tea Catechins (Gtc) Through Hplc

Green tea (Camellia sinensis) is a prosperous source of polyphenols, especially catechins. In the current research, an effort was made to optimize the extraction conditions for maximum yield of catechins from the local green tea Qi-Men. For the purpose, three different solvents were used, i.e., aqueous ethanol (50%), aqueous methanol (50%), and water at different time intervals (20, 40, and 60 min). Green tea catechins were quantified through HPLC using a C18 column and UV detector. The antioxidant activity of green tea catechins was measured through in vitro tests including DPPH radical scavenging ability and antioxidant activity. Results showed that extraction through aqueous ethanol resulted in maximum yield of green tea catechins (17400 ± 0.19 mg/100 g green tea leaves. Moreover, epigallocatechin, epigallocatechin gallate, epicatechin gallate, and epicatechin ranged from 4.26 ± 0.09 to 6.4 ± 0.2, 12.1 ± 0.123 to 17.7 ± 0.3, 1.32 ± 0.03 to 1.81 ± 0.02, 5.48 ± 0.099 to 8.6 ± 0.2 g/100 g of dry-extract, respectively. Furthermore, highest antiradical (80.65 ± 3.69%) and antioxidant activity (67.12 ± 3.08%) were observed in catechins extracted through aqueous ethanol.     

内部沸腾法提取茶多酚工艺优化及其与水提法的比较

采用内部沸腾法提取茶多酚,研究解吸剂(乙醇)浓度、解吸时间、解吸剂料液比、提取剂(热水)料液比、提取时间、提取温度等六个因素对茶多酚得率的影响,在单因素实验基础上,设计正交实验,优化茶多酚提取条件。与水提法进行比较,考察两种工艺对儿茶素组分以及抗氧化活性的影响。结果表明,内部沸腾法提取茶多酚的最佳工艺参数为:以50%的乙醇为解吸剂、室温解吸10 min、解吸剂料液比1:6 g/mL;再以水为提取剂、提取剂料液比1:110 g/mL、100℃提取10 min,在此最优工艺条件下茶多酚得率为22.45%±0.11%。与水提法相比,内部沸腾法将茶多酚得率提高了11.53%,高温提取时间缩短近80%,减少了高温对茶多酚活性的破坏,保留了更多的表儿茶素,茶多酚抗氧化活性显著(P<0.05)增强,是一种经济、快速、有效的提取方法,具有较好的工业化生产前景。     

Ultrasound assisted extraction of oils from apple seeds: A comparative study with supercritical fluid and conventional solvent extraction

The aim of this study was to optimize the processing conditions for the extraction of apple seed oil by applying ultrasounds (UAE) using hexane as solvent. A response surface methodology with a central composite design identified the following optimized parameters: 56 W of power (64% amplitude), 30 min at 30 °C. The obtained oil presented a fatty acids profile rich in linoleic acid (35.5 ± 2.8 g/100 g) with an antioxidant activity equal to 0.22 ± 0.1 mg Trolox/g oil and a total phenolic content of 0.16 ± 0.1 mg GAE/o oil. The chemical characteristics of the UAE oil were then compared with those obtained for the oils extracted with Soxhlet (SE) and supercritical fluid (SFE). UAE gave similar yields (17.20 ± 2.3%) compared to SFE (19.3 ± 2.1%), and SE (19.1 ± 1.5%). Fatty acid profiles were also not significantly different (p < 0.05). The UAE oil was richer in antioxidants like phloretin and phloridzin. Amygdalin was detected in UAE and SE oils but not in SFE oil. The comparison among the processes showed that the UAE was a more efficient and time-saving technique, while SFE was able to provide an oil free from amygdalin suitable for possible further food applications.     

Influence of pressurised liquid extraction and solid–liquid extraction methods on the phenolic content and antioxidant activities of Irish macroalgae

The efficiencies of pressurised liquid extraction (PLE) and a traditional solid–liquid extraction (SLE) at extracting antioxidant polyphenols from Irish macroalgae Ascophyllum nodosum, Pelvetia canaliculata, Fucus spiralis and Ulva intestinalis were compared. PLE was more effective for extracting polyphenols with acetone/water (80:20); however, when food‐friendly solvents of ethanol/water (80:20) and water were employed, SLE resulted in higher phenolic content in brown macroalgal extracts. For example, the Fucus spiralis SLE water and ethanol/water extracts displayed total phenolic contents (TPCs) of 130.58 ± 2.78 and 142.81 ± 1.77 μg phloroglucinol equivalents (PGE) mg^?1 sample, respectively, compared with TPCs of 90.79 ± 1.16 and 124 ± 6.54 μg PGE mg^?1 sample for the corresponding PLE extracts. All SLE aqueous ethanolic macroalgal extracts possessed higher DPPH radical scavenging abilities (RSA) and ferric reducing antioxidant power (FRAP) than their PLE equivalents . This study indicates that the application of high extraction temperatures (50–200 °C) and pressures (500–3000 psi) used in PLE does not enhance the antioxidant activities of macroalgal extracts relative to SLE extraction. The ability to produce antioxidant food‐friendly macroalgal extracts using SLE could represent significant cost reductions on an industrial scale further enhancing the potential of macroalgal polyphenols to be used in functional food preparations.     

Recovery of phenolic compounds from peach pomace using conventional solvent extraction and different emerging techniques

The study compared high-pressure, microwave, ultrasonic, and traditional extraction techniques. The following extraction conditions were implemented: microwave-assisted extraction (MAE) at 900 W power for durations of 30, 60, and 90 s; ultrasonic-assisted extraction (UAE) at 100% amplitude for periods of 5, 10, and 15 min; and high-pressure processing (HPP) at pressures of 400 and 500 MPa for durations of 1, 5, and 10 min. The highest yield in terms of total phenolic content (PC) was obtained in UAE with a value of 45.13 ± 1.09 mg gallic acid equivalent (GAE)/100 g fresh weight (FW). The highest PC content was determined using HPP-500 MPa for 10 min, resulting in 40 mg GAE/100 g, and MAE for 90 s, yielding 34.40 mg GAE/100 g FW. The highest value of antioxidant activity (AA) was obtained by UAE in 51.9% ± 0.71%. The PCs were identified through the utilization of Fourier transform infrared (FTIR) spectroscopy and high-performance liquid chromatography (HPLC). Utilizing multivariate analysis, the construction of chemometric models were executed to predict AA or total PC of the extracts, leveraging the information from IR spectra. The FTIR spectrum revealed bands associated with apigenin, and the application of HPP resulted in concentrations of 5.41 ± 0.25 mg/100 g FW for apigenin and 1.30 ± 0.15 mg/100 g FW for protocatechuic acid. Furthermore, HPLC analysis detected the presence of protocatechuic acid, caffeic acid, p-coumaric acid, and apigenin in both green extraction methods and the classical method. Apigenin emerged as the predominant phenolic compound in peach extracts. The highest concentrations of apigenin, p-coumaric acid, and protocatechuic acid were observed under HPP treatment, measuring 5.41 ± 0.25, 0.21 ± 0.04, and 1.30 ± 0.15 mg/kg FW, respectively.     

Artificial neural network modeling and optimization of ultrahigh pressure extraction of green tea polyphenols

In this study, the ultrahigh pressure extraction of green tea polyphenols was modeled and optimized by a three-layer artificial neural network. A feed-forward neural network trained with an error back-propagation algorithm was used to evaluate the effects of pressure, liquid/solid ratio and ethanol concentration on the total phenolic content of green tea extracts. The neural network coupled with genetic algorithms was also used to optimize the conditions needed to obtain the highest yield of tea polyphenols. The obtained optimal architecture of artificial neural network model involved a feed-forward neural network with three input neurons, one hidden layer with eight neurons and one output layer including single neuron. The trained network gave the minimum value in the MSE of 0.03 and the maximum value in the R² of 0.9571, which implied a good agreement between the predicted value and the actual value, and confirmed a good generalization of the network. Based on the combination of neural network and genetic algorithms, the optimum extraction conditions for the highest yield of green tea polyphenols were determined as follows: 498.8 MPa for pressure, 20.8 mL/g for liquid/solid ratio and 53.6% for ethanol concentration. The total phenolic content of the actual measurement under the optimum predicated extraction conditions was 582.4 ± 0.63 mg/g DW, which was well matched with the predicted value (597.2 mg/g DW). This suggests that the artificial neural network model described in this work is an efficient quantitative tool to predict the extraction efficiency of green tea polyphenols.     

Improving the pressing extraction of polyphenols of orange peel by pulsed electric fields

The influence of pulsed electric field (PEF) treatment on the extraction by pressing of total polyphenols and flavonoids (naringin and hesperin) from orange peel was investigated. A treatment time of 60 μs (20 pulses of 3 μs) achieved the highest cell disintegration index (Zp) at the different electric field strengths tested. After 30 min of pressurization at 5 bars, the total polyphenol extraction yield (TPEY) increased 20%, 129%, 153% and 159% for orange peel PEF treated at 1, 3, 5 and 7 kV/cm, respectively. A PEF treatment of 5 kV/cm to the orange peels increased the quantity of naringin and hesperidin in the extract of 100 g of orange peels from 1 to 3.1 mg/100 g of fresh weigh (fw) orange peel and from 1.3 to 4.6 mg100 g fw orange peel respectively. Compared to the untreated sample, PEF treatments of 1, 3, 5 and 7 kV/cm increased the antioxidant activity of the extract 51%, 94%, 148% and 192%, respectively.The results of this investigation demonstrate the potential of PEF as a gentle technology to improve the extraction by pressing of polyphenols from fresh orange peel. This procedure enhances the antioxidant capacity of the extracts, reduces extraction times and does not require using organic solvents.Industrial relevanceProcessing of orange fruits to obtain fresh juice or citrus-based drinks generates very large amounts of byproduct wastes, such as peels that are a rich source of polyphenols mainly flavonoids. Extraction of these compounds from orange peels is a crucial step for use of these compounds in the food and pharmaceutical industries as antioxidants. PEF-assisted extraction by pressing of polyphenols from fresh orange peels stands as an economical and environmentally friendly alternative to conventional extraction methods which require the product to be dried, use large amounts of organic solvents and need long extraction times.     

Extraction of caffeine and catechins using microwave-assisted and ultrasonic extraction from green tea leaves: an optimization study by the IV-optimal design

In this research, optimal conditions for extraction of caffeine and polyphenols were established from Iranian green tea leaves. In the first step, caffeine was extracted with efficacy about 86% versed to 4.5% of EGC + EGCG. The EGCG + EGC was extracted from partially decaffeinated green tea leaves through microwave-assisted extraction (MAE) and ultrasound-assisted extraction (USE) with efficiency levels of 95 and 85%, respectively. The best results for the MAE process were obtained with 7.8 min and three number of extraction cycles and for the USE process were as followed: time 57 min, temperature 65 °C, and the number of extraction cycles 3. The total phenol content values at the best conditions of MAE and the USE processes were 125 ± 5 and 96 ± 6 mg gallic acid/g DW. The 50% inhibition (IC₅₀) on 1,1-diphenyl-2-picrylhydrazyl (DPPH) were 56 and 66 mg/g of phenol for the MAE and USE processes.     

茶酒糟中茶多酚提取工艺优化及其抗氧化活性的研究

该试验以茶酒糟为原料,乙醇为提取溶剂,采用水浴振荡法提取茶多酚,通过单因素试验探究乙醇体积分数、料液比、提取时间、温度对茶多酚提取量的影响,在此基础上,通过正交试验优化茶多酚的水浴振荡乙醇提取工艺,并考察茶多酚对羟自由基（·OH）、1,1-二苯基-2-三硝基苯肼自由基（DPPH·）的清除能力。结果表明,从茶酒糟中提取茶多酚的最佳提取工艺是：乙醇体积分数60%,料液比1∶30（g∶mL）,提取时间12 min,提取温度75 ℃。在此优化条件下,茶多酚的提取量为41.52 mg/g。从茶酒糟提取得到的茶多酚对·OH和DPPH·最大清除率分别达到91.7%、93.7%,表明茶多酚具有一定的清除自由基的能力,具有较强的抗氧化活性。     

啤酒花多酚的提取工艺及抗氧化活性的研究

通过单因素和正交试验确定了酒花多酚的最佳提取工艺:浸提剂为70%丙酮,料液比1:25(g/ml),回流提取温度45℃,提取时间为1h,在此条件下多酚的提取量达到47.29mg/g干酒花。抗氧化实验结果显示酒花多酚对DPPH自由基的清除能力(IC506.72μg/ml)优于抗坏血酸(IC508.79μg/ml)和单宁酸(IC507.68μg/ml),弱于茶多酚(IC505.77μg/ml);酒花多酚的还原力(EC500.111mg/ml)与抗坏血酸(EC500.101mg/ml)接近,弱于单宁酸(EC500.079mg/ml)和茶多酚(EC500.072mg/ml);酒花多酚对小鼠肝匀浆脂质过氧化产生丙二醛(MDA)的抑制能力(IC500.179mg/ml)优于单宁酸(IC500.462mg/ml),弱于茶多酚(IC500.136mg/ml)。     

Yerba mate tea (Ilex paraguariensis): Phenolics,antioxidant capacity and in vitro inhibition of colon cancer cell proliferation

Mate tea (MT) is a rich source of phenolic compounds that vary depending on geographical origin and mode of preparation. Total phenolic concentration and antioxidant capacity of Mate tea (Ilex paraguariensis) products were determined in this work. In addition, a representative MT was tested for in vitro inhibition of human colon carcinoma cell proliferation. Total polyphenol concentration, was measured using Folin–Ciocalteau method, ranged from 90 to 176 mg gallic acid eq (GAE)/g dry leaves (DL) in traditional MT and from 40 to 113 mg GAE/g DL in MT added with other flavouring ingredients. It was estimated that a cup of tea (250 ml) containing one teaspoon (5 g) of instant MT could provide an average intake of 1.5 g GAE. Fresh tea (FT) from Mate leaves displayed high antioxidant capacity (85 ± 1%) and preferentially inhibited 50% of net growth of human colorectal adenocarcinoma cells CaCo-2 (GI₅₀ = 1.0 ± 0.03 μg/ml) and HT-29 (GI₅₀ = 105.2 ± 15.2 μg/ml) when compared with the CCD-33Co normal colon fibroblast cell line (GI₅₀ > 300 μg/ml). MT inhibited in vitro colon cancer cell proliferation possibly mediated via pro-oxidant activities, therefore represents a potential source of chemopreventive agents that deserve further investigation.     

Frequency and wave type effects on extractability of oleuropein from olive leaves by moderate electric field assisted extraction

The moderate electrical field (MEF) process was used to reduce the process time (t) of oleuropein extraction from olive leaves. MEF process was performed with methanol-water (4:1 v/v) with sine wave-SN and square wave-SQ at 30 V/cm with different frequencies (1, 1000, and 2000 Hz). The conventional extraction (CE) method was performed for 8 h in methanol-water (4:1 v/v) mixture at 40 °C. The effects of MEF conditions on t, effective electrical conductivity (EEC), cell disintegration (Zc) and extraction performance coefficient (EPC) were determined. SN provided desired extraction yield in a shorter time than SQ (p < 0.05). The necessary extraction time for target extraction yield (21.6 ± 1.0 mg Oleuropein/g dm) increased as the frequency decreased (p < 0.05). SN resulted in higher Zc values compared to SQ (p < 0.05). EPC of MEF was higher than CE (p < 0.05). It is concluded extractability of the oleuropein at any given extraction time could be improved by MEF compared to CE.