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Résumé :
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Short-path distillation (SPD), a special high-tech thermal separation technique operating at high vacuum, was used in order to increase the citral concentration in lemongrass essential oil, without adding any extra components to the system, causing minimal thermal impact and reaching high quality for the essential oil extracted at the distillate stream. Experiments were carried out using a centrifugal molecular distillation unit with an evaporator temperature (EVT) from 60 to 120 °C and a feed flow rate (Q) from 1.5 to 4.5 mL·min-1. Experimental protocols for oil and fat analysis were used to characterize the materials extracted. Results (obtained using GC-MS) showed that bSPD was successful in the separation and purification of essential oil. High-quality essential oil was confirmed because of citral concentration increases from 19.816 mgcitral·mL-1(initial sample) to 40.963 mgcitral·mL-1 (at 120 °C and 4.5 mL·min-1), reaching a concentration of the bioactive compound (citral) in the distillate stream of 2.1 times the concentration in the original sample. The density, dynamic viscosity, and free fatty acids were 0.901 g·cm-3, 2.069 mPa·s-1, and 1.26 wt % (oleic acid), respectively, satisfying the oil quality criterion and avoiding thermal degradation.
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