Optimization of ultrasound-assisted extraction of bioactive compounds from wild garlic (Allium ursinum L.)

Abstract

Ultrasound-assisted extraction was used for extraction of bioactive compounds and for production of Allium ursinum liquid extract. The experiments were carried out according to tree level, four variables, face-centered cubic experimental design (FDC) combined with response surface methodology (RSM). Temperature (from 40 to 80 °C), ethanol concentration (from 30% to 70%), extraction time (from 40 to 80 min) and ultrasonic power (from 19.2 to 38.4 W/L) were investigated as independent variables in order to obtain the optimal conditions for extraction and to maximize the yield of total phenols (TP), flavonoids (TF) and antioxidant activity of obtained extracts. Experimental results were fitted to the second order polynomial model where multiple regression and analysis of variance were used to determine the fitness of the model and optimal condition for investigated responses. The predicted values of the TP (1.60 g GAE/100 g DW), TF (0.35 g CE/100 g DW), antioxidant activity, IC50 (0.71 mg/ml) and EY (38.1%) were determined at the optimal conditions for ultrasound assisted extraction: 80 °C temperature, 70% ethanol, 79.8 min and 20.06 W/L ultrasonic power. The predicted results matched well with the experimental results obtained using optimal extraction conditions which validated the RSM model with a good correlation.

Ultrasound Assisted Extraction for the Recovery of Phenolic Compounds from Vegetable Sources

“…It is for this reason that the extraction solvent must be selected according to the solubility of the compounds to which the process is directed. Furthermore, the toxicity, cost, and availability must also be taken into account [34]. Solvents such as methanol or ethanol have a significantly lower polarity when compared to water and this favors the solubility and diffusion of the phenolic compounds by reducing the dielectric constant of the solvent.…”

“…These authors point to a synergistic effect among the solvents, since water acts as a swelling agent of the plant matrix, increasing the contact surface, while ethanol induces the rupture of the bond between the solutes and the matrix. Nevertheless, Tomsik [34] and Muñiz-Márquez [36] indicated that at 70% of ethanol concentration in solvents resulted in better extraction yields, due to the polarity of the compounds presented in the samples.…”

“…Among the different methods of RSM reported in Table 2, the design by Box-Behnken is the most frequently reported [46], followed by the central composite design [51] and the face-centered cubic experimental design [34]. The regression analysis on the results obtained from the implementation of these models generates polynomial equations (using the significant values of the estimated regression coefficients), from which the optimal conditions of the process are determined.…”

Ultrasonic-extraction of phenolic compounds from Phyllanthus urinaria: optimization model and antioxidant activity

“…As the ultrasonic time increases, the extraction yield increases initially and then decreases when a maximum yield at 30 min is achieved. Ultrasound with mechanical agitation effect, cavitation effect, and thermal effect can improve the mass transport and facilitate the release of compounds from the extracted materials (Carrera et al, 2012;Tomšik et al, 2016). However, the long ultrasonic time can degrade the phenolic compounds, leading to the decrease of the extraction yield (Carrera et al, 2012;Ddabas & Koca, 2016).…”

Determination of triterpenoids, carotenoids, chlorophylls, and antioxidant capacity in Allium ursinum L. at different times of harvesting and anatomical parts

“…Such plants may include wild garlic, which is a valuable component in the human diet. The compounds of wild garlic have potent biological activity [1]. It is used as a spice in the cuisines of many nations, and it has been used for centuries in medicine.…”