A membrane-based study for the recovery of polyphenols from bergamot juice

Methods to concentrate and purify bioactive compounds have become a subject of dramatically increased interest in the last several decades. Bergamot is the common name of the fruit Citrus Bergamia Risso, an endemic plant of the Calabrian region in Southern Italy, whose volatile fraction is widely used in the cosmetic and perfumery industries. The juice, considered a waste of the essential oil production, contains a considerable amount and variety of flavonoids and flavonoid glycosides having important health implications. In this work, a membrane-based process was investigated for the separation and concentration of polyphenols in the bergamot juice, in order to develop a natural product enriched in polyphenols suitable for nutraceutical applications. The process was based on the initial clarification of depectinised bergamot juice by ultrafiltration (UF), devoted to the removal of suspended solids. The clarified juice was then submitted to different UF and NF processes in order to evaluate the effect of the nominal molecular weight cut-off (MWCO) on the rejection of the membranes towards sugars, organic acids and polyphenols. The performance of selected membranes was also evaluated in terms of productivity and composition of produced permeate and retentate fractions.