Résumé
Carotenoids are a group of natural pigments of fruits and vegetables with high antioxidant capacity, and are also precursors to the formation of specific aromas. The objective of this work was to evaluate the distribution of carotenoids and aromatic compounds of watermelon juice during sequential microfiltration and diafiltration operations. The microfiltration tests were performed in juice with previous enzymatic treatment, using a membrane of 0.8 mu m at an average pressure of 0.1 MPa, temperature of 50 degrees C and flow velocity of 6.0 m.s(-1), with 2 L constant feed volume. A retention diafiltration process was then performed using potable water. The concentration of beta-carotene, trans and cis-lycopene isomers, total soluble solids (SST), pH, titratable acidity, total dry matter and aromatic components were determined in all streams derived from the process. The average flow obtained in the microfiltration stage was 114 L.h(-1).m(-2) at a volumetric reduction factor of 10. The concentration of lycopene in the retentate after the microfiltration was 657. 40 mg.kg(-1). The diafiltration step reduced the SST to 11.1 +/- 0.3 g.kg(-1). The enzymatic treatment did not influence the composition of the aromatic compounds of the juice; however, from the microfiltration and diafiltration processes currents were obtained with a distribution of aromatic compounds different from the fresh juice.