Differential Recovery of Terpene Hydrocarbons and Oxygenated Compounds from Condensates Containing Essential Oil Discharged during Concentration of Citrus Juices Using a Ceramic Membrane

Abstract

Essential oils of citrus fruits have many uses in consumer products so that efficient methods for their isolation are needed. Membranes are often used in the separation process but a common problem is that the flux through the membranes decreases with time. In the present study we examined whether ceramic membranes might be better at maintaining the flux at acceptable levels. To test the membranes, we attempted differential recovery of nonpolar terpene hydrocarbons and aqueous oxygenated compounds from condensates produced as a by-product during the concentration of citrus juices. When zirconia membranes (ZrO 2 -UF, cut-off molecular weight 50,000 and ZrO 2 -MF, pore size 0.08 m) were used, little decrease in the flux was observed during filtration. The nonpolar terpene hydrocarbons were retained while more polar oxygenated flavor compounds passed through the membrane. The percentages of alcohols, esters, and aldehydes in the permeate increased markedly compared with their percentages before filtration. When the condensate from the concentration process of citrus juice sampled from a juice factory was filtered using ZrO 2 -UF, the hydrocarbons was concentrated, and a water-soluble essence consisting primarily of oxygenated compounds was obtained in the permeate.

Improved concentration of citrus essential oil by solvent extraction with acetate ionic liquids

“…Emerging technologies have also been tested, and for example membrane separation and supercritical fluid extraction are already in industrial use. Membrane separations afford a high quality product due to the operation at low temperatures, along with other concomitant advantages; but they present typical problems of membrane-based processes, such as tendency to clog and maintenance costs [1,11,12]. Extraction with supercritical fluids also avoids high temperatures and direct distillation processes in the deterpenation of essential oils, with CO2 being the most commonly employed supercritical fluid, since it is non-toxic, non-flammable, and has a critical temperature of 31 ºC; but again, problems inherent to supercritical fluid technologies, such as investment, safety, and operational costs, are a handicap [1,4,[13][14][15].…”

Effect of Deterpenated Origanum majorana L. Essential Oil on the Physicochemical and Biological Properties of Chitosan/β-Chitin Nanofibers Nanocomposite Films

“…For this reason, it is important to carry out a deterpenation of the essential oils to separate the terpenes from the oxygenated terpene derivatives (terpenoids) to improve the stability and the bioactive properties of Eos [ 6 ]. Deterpenation has been done using different methods namely vacuum distillation, solvent extraction, membrane technologies, and extraction with ionic liquids [ 4 , 5 , 6 , 7 , 8 , 9 , 10 ].…”

Deep Deterpenation of Citrus Essential Oils Intensified by In Situ Formation of a Deep Eutectic Solvent in Associative Extraction

“…6,7 Therefore, the essential oils are usually purified by a deterpenation process to remove large parts of the undesirable terpenes. 8 Deterpenation of CEOs was previously carried out via different methods, 9 such as vacuum distillation, 10 liquid−liquid extraction, 11,12 membrane separation, 13 and extraction with supercritical fluids. 14 Of these methods, liquid−liquid extraction is preferred; the mild operation conditions required for this method preserve the bioactive and organoleptic properties of the oil, and it has several other advantages, including lower energy requirements and lower operating costs.…”