SEQUENTIAL PROCESSING OF Psidium guajava']java L. LEAVES: STEAM DISTILLATION AND SUPERCRITICAL FLUID EXTRACTION

Extracts from the leaves of Psidium guajava L have been studied due to their importance as a source of natural antioxidant components with possible applications in the pharmaceutical and food industries. In this work, the sequential use of steam distillation and supercritical fluid extraction was studied to obtain the essential oil from the leaves and non-volatile compounds from the residue. The non-volatile compounds were obtained by CO2 supercritical extraction. Experiments were performed in a automated pilot-scale extractor at constant pressure of 15 MPa, at 313 K and 333 K in three different flow rate conditions. The analysis of the essential oil with GC-MS identified E-caryophyllene, beta-selinenel, alpha-selinene, selin-11-en-4-alpha-ol and E-nerolidol as main compounds. Antioxidant activity was observed in all extracts. The experimental extraction curves were compared to simulated ones predicted by a mathematical model based on mass transfer principles with two adjustable parameters. The model used fitted accurately the experimental data.