Microchannels Effective Method for the Extraction of Oleuropein Compared with Conventional Methods

Mahnaz Yasemi,Mehdi Ardjmand,Amir Heydarinasab,Masoud Rahimi

doi:10.1155/2017/6594156

Abstract

Different methods of oleuropein extraction from olive leaf were investigated, including maceration, soxhlet, ultrasonic-assisted extraction, and microchannel. In current research, a response surface methodology (RSM) was used for prediction of the optimal values of parameters affecting the extraction of oleuropein through two methods of ultrasound and microchannel. Frequency (F), temperature (T), and power of ultrasound (P) were the parameters which were studied in ultrasound method, but in microchannel system effects of pH and temperature (T), volumetric flow rate ratio of two phases (VR), and contact time (CT) of two phases were optimized. UV detector device at 254 nm was used to recognize oleuropein through comparison of the retention time of the extracts with standard compound in chromatogram. The analysis of extracts was performed using HPLC. Optimum conditions for ultrasound were obtained as follows:F=80 kHz,T= 25°C, andP=100 w. Using these optimum conditions, the extraction of oleuropein was 81.29%. Amount of oleuropein extraction by microchannel method in optimum conditions was 96.29%, which was way more than other applied methods. Microchannel system as a continuous method has many advantages including low solvent consumption, being environment friendly, short time for extraction, and high efficiency.

Highlights

Olive leave as a photochemical source of phenol and flavonoid [1] has antioxidant [2,3,4,5,6] and antibacterial [7,8,9,10] properties
The present study is aimed at extracting the oleuropein from olive leaves via diverse extraction approaches and to compare these approaches together. Another goal of this study is to develop and optimize a green, easy, reliable, repeatable, and inexpensive process for extraction of oleuropein as an important phenolic compound from olive leaf
For selecting the best solvent in each method, the following procedure should be followed: in maceration method, at each run, 10 g of olive leave described in preparation stage should be separately mixed with different solvents including ethanol absolute (80% and 20%), methanol (80% and 20%), and ethyl acetate

Summary

Introduction

Olive leave as a photochemical source of phenol and flavonoid [1] has antioxidant [2,3,4,5,6] and antibacterial [7,8,9,10] properties. Highest amount of phenol derivatives in olive leaf is oleuropein, whose amount depends on harvest time and varies between 17 and 23% [11]. Amount of oleuropein in ripe fruit is more than growing fruit [17]. Different factors such as extraction method, type of solvent, temperature, and extraction time affect efficiency. Extraction efficiency of traditional methods is low and much solvent is needed; damage can be caused to environment [21]

Methods

Results

Conclusion