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

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 ( ), temperature ( ), and power of ultrasound ( ) were the parameters which were studied in ultrasound method, but in microchannel system effects of pH and temperature ( ), 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: = 80 kHz, = 25 ∘ C, and = 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.

Extraction of oleuropein from olive leaves and applicability in foods

“…Achat et al (2012) obtained a much higher yield of oleuropein (414.3 mg/g) after maceration of olive in ultrasound bath at 16°C for 45 min, which is comparable to solid-liquid extraction yields. The highest yield (812.9 mg/g) was described by Yasemi et al (2017), who extracted oleuropein in methanol: water (80:20) using an ultrasound bath of 25 kHz. In contrast, lower yields of 134.5 and 7.0 mg/g using ultrasound bath were reported by Ismaili et al (2016) and Deng et al (2017), respectively.…”

“…In recent years, other nonconventional technologies have been proposed for the extraction of oleuropein, including microfluid systems (microchannels) and infrared-assisted methods (Table 3). In particular, microchannels have gained extensive attention because of higher yields of oleuropein achieved, low operational costs, and low environmental impact of the procedure (Yasemi et al, 2017). In addition, intense research activities are currently being addressed to include special statistical approaches for the optimization of the extraction of oleuropein, such as Artificial Neural Networks (Yasemi, 2020), Central Composite Design (CCD) (Lamprou et al, 2020), and Box Wilson-Central Composite Rotatable Design (Vural et al, 2020).…”

Oleuropein: Methods for extraction, purifying and applying

“…In this research, the microchannel method was compared to a conventional method, and the authors observed higher yield in extraction, simplicity of operation, and an economical and environmentally friendly procedure, all of which were undoubted advantages. Yasemi et al (2017) evaluated the efficiency of the method of microchannels for extracting oleuropein, were obtained a yield of 96.29% of oleuropein using this system with optimized operating parameters; this value was much higher than the yields found through maceration, Soxhlet and ultrasound-assisted methods. Heydarid et al, (2018) studied the optimization of oleuropein extraction from organic extracts using a microfluidic device and response surface methodology.…”

“…In addition, the results showed that Soxhlet was more efficient in extracting oleuropein compared to the cold extraction technique (Yateem et al, 2014). Yasemi et al (2017) also evaluated different extraction methods, including maceration, soxhlet, ultrasound and microchannel, with soxleth extraction showing the greatest recovery among conventional techniques (62%). In addition, different combinations of solvents were also tested, where for soxleth the best combination was ethanol: water (80:20).…”

Potential Uses of Olive Oil Secoiridoids for the Prevention and Treatment of Cancer: A Narrative Review of Preclinical Studies

“…The most commonly used techniques involve conventional solid-liquid extraction and ultrasonic extraction [ 41 ]. Recently, a number of non-conventional technologies have been proposed for the extraction of oleuropein [ 44 ], including separation by membrane, infrared-assisted methods, accelerated solvent extraction, extraction with supercritical fluids [ 45 ], acid hydrolysis by sulfuric acid and microchannel devices [ 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 ].…”