INFLUENCE OF APPLICATION OF MEMBRANE SEPARATION ON THE ANTIOXIDANT ACTIVITY OF Citrus limon L. Burm. JUICE

The Citrus Limon is rich in important natural chemical components (citric and ascorbic acid, vitamin B, minerals and flavonoids) that have shown health-related properties like antioxidant, anticancer, antiviral, antimicrobial, anti-inflammatory, antiallergic and antidiabetic activities, and effects on capillary fragility. In Italy, a typical product is the lemon cultivated in town of Rocca Imperiale, located in Calabria. This product is characterized by the presence of high concentration of juice rich in health promoting substances which are able to counteract the oxidative damage. Numerous studies have been focusing on recovery of Citrus Limon compounds by using of efficient extraction methods. The most common operation applied in many industrial processes is the extraction by organic solvents. The disadvantage of solvent extraction has however been recognized since it required large amounts of organic solvents which are considered unsafe for food aims and involves high capital costs. The aim of this study was to evaluate an alternative approach, based on ultrafiltration (UF) membrane processes, for the extraction of antioxidants compounds from juices of lemons cultivated in Rocca Imperiale. In this study, UF-process was performed by using membranes with high molecular weight cut-off to obtain UF-fractions with distinctive concentrations of phenols and flavonoids. The antioxidant activity of the UF-fractions were then assessed by different in vitro assays developed for measuring the antioxidant capacity of food and beverages. So, for the investigation of the radical scavenging activity DPPH and ABTS test were performed; FRAP test was used to evaluate the effect on iron, one of the most important ions involved in oxidation process.