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Showing 2 results for Extraction Kinetics
Mohsen Zandi, Ali Ganjloo, Mandana Bimakr,
Volume 18, Issue 121 (3-2022)
Abstract
The aim of the present research was modeling and optimizing the ultrasound-assisted hydrodistillation (USHD) of essential oil extraction process and comparing the effects of hydrodistillation (HD) and USHD techniques on the musk willow (Salix aegyptiaca L.) essential oil. Sonication time (15-45 min), ultrasound power level (100-500 W) and water to plant ratio (3-10 (v/w)) were varied in order to maximize S. aegyptiaca L.essential oil yield, total phenolic content (TPC) and IC50. The effect of sonication time and sound power levels on the essential oil yield, TPC and IC50 was significant at the 5% level. Although increasing water to plant ratio parameter significantly resulted in a higher yield (p<0.05), however, this parameter no significant effect the TPC and IC50 (p>0.05). The optimum parameters were sonication time of 39 min, sound power levels of 189 w, and water to plant ratio of 6.8 V/W. Under optimum conditions, both USHD and HD methods were used for essential oil extraction. USHD showed a significantly higher amount of extraction yield (0.108±0.009% (v/w)) compared to the HD (0.081±0.01% (v/w)) (p<0.05). Compared to the HD extraction, the USHD resulted in a shorter extraction time, less energy consumption, higher antioxidant properties and a higher extraction yield. Physical properties of OAHD and HD essential oils were not significantly different (p>0.05). Among the four kinetics models, the sigmoid model was shown to be the best one. This model can be used for modeling the kinetics of essential oil extraction by both HD and USHD.
Volume 19, Issue 7 (12-2017)
Abstract
In this study, the effect of three amplitudes of Ultrasound-Assisted Solvent Extraction (UASE) (0, 20 and 40%; 100W, 30 kHz; the 0% treatment serving as control) on kinetics, thermodynamic, rosmarinic acid content, total phenolics, antioxidant activity, and antimicrobial activity of Ocimum basilicum L. (basil) extract at different temperatures (25, 35 and 45°C) was evaluated. Increases in ultrasound amplitude and temperature increased yields and biological activities of extracts. The highest rosmarinic acid content, total phenolics, antioxidant and antimicrobial activity were obtained for samples treated with UASE at 40% amplitude and 45°C. The kinetics of extraction were evaluated based on a second order mechanism. Increases of amplitude and temperature significantly increased saturated extraction Capacity (Cs), initial extraction rate (h), and rate constant of extraction (k). The thermodynamic aspects of the extraction process showed that samples treated with UASE at 40% amplitude had higher activation Energy (Ea), frequency factor (A), enthalpy (ΔH++) and entropy (ΔS++) than control. UASE at 40% amplitude and control did not significantly differ in thermodynamic parameters. Results also showed very good linear relationships with high correlation coefficients between Ea and ΔH++ and, A and ΔS++. Therefore, ultrasound can affect thermodynamic aspects and kinetics of extraction of basil extract and improve its biological activity.
