Citrus medica L. cv Diamante aroma recovery by pervaporation

Aroma are a blend of organic and volatile compounds present in small traces in many natural sources of plant origin. Aroma extraction by means of pervaporation (PV) is a valid alternative to the other commonly used techniques. PV, in fact, allows recovery of volatile compounds at low temperatures preserving their molecular integrity, avoiding the use of harmful solvents with a low energy consumption. Some successful examples of aroma recovery and concentration by PV are already reported in literature [1-3]. The aim of this work was the extraction of volatile compounds from Citrus medica L. cv Diamante peel by PV. Substances contained in its peel have been studied for their pharmacological properties, and the essential oil is used for its fragrance and freshness in perfumery; in food industry as flavoring for liqueurs, sweets and beverages; and in aromatherapy to enhance well-being. The pharmaceutical research interest for C. medica is due to its biological properties that could make it an ideal candidate for the treatment of diseases due to oxidizing agents damage [4]. In this work, extractive solutions with peel in hydroalcoholic mixtures at different concentrations were tested by PV using commercial POMS and lab-made SBS membranes previously characterized. Tests were carried out at 35°C to avoid the degradation of the more thermolabile compounds. In order to identify the more common components and to evaluate membranes performance in terms of flux and selectivity, GC-MS analysis on the feed solution and permeate were carried out. The analysis showed that volatile compounds, such as limonene, alpha-pinene, beta-pinene, sabinene and thujene, easily permeate the membrane. On the contrary, the coumarin citropten is retained. The antioxidant activity was also evaluated in order to verify the permeation through the membrane of components with a potential pharmacological interest.