Supercritical extraction of leaves of Eugenia uniflora L.

Author(s)

Camila Arantes Peixoto

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos
• Defense date: 2008-02-12

Examining board members

Fernando Antonio Cabral; Carmen Lucia Queiroga; Cintia Bernardo Gonçalves; Eduardo Augusto Caldas Batista; Silvania Regina Mendes Moreschi; Antonio José de Almeida Meirelles

• Advisor: Alessandra Lopes de Oliveira; Fernando Antonio Cabral

Abstract

Examined in the literature that there is not the characterization of extracts obtained by supercritical fluid from the leaves of Eugenia uniflora L. (Surinam cherry), this work aimed to obtain these extracts varying conditions of supercritical extraction as regards temperature and pressure of 30, 40, 50 and 60 °C an d 100, 150, 200, 250 and 300 bar. It was found that the optimum operational conditions for the process were 40 ºC and 300 bar and 60 ° C, at pressures of 250 and 300 bar, which corresponded to yield of: 3,68; 3,54 and 3,96 %, respectively. The extracts of the leaves obtained by supercritical extraction, by hydrodistillation and by solid phase microextraction were characterized. The majority compounds found in the extract obtained by hydrodistillation were curzerene (34,76 %), germacrene B (11,84 %) and C15H20O2 (9,56 %). The compounds: ß-elemene, ß- caryophyllene and ?-elemene are presented in the essential oil of the leaves as well in the extract obtained by solid phase microextraction. The major compound presented in supercritical extracts was C15H20O2 followed by curzerene and germacrene B. By the DPPH antioxidant activity method, the extract obtained with hydrated alcohol presented the higher antioxidant activity, because the higher concentration of total phenols among all the extracts obtained of the leaves of E. uniflora. The value of antioxidant activity expressed in IC50 for the hydrated alcohol extract of the leaves of E. uniflora was 16,95 g/mL. The classical thermodynamic modeling was used to estimate the solubility of major components of the extract (AU)