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| Author(s): |
Mirelle Dogenski
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Pirassununga. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT) |
| Defense date: | 2013-10-04 |
| Examining board members: |
Alessandra Lopes de Oliveira;
Gelson José Andrade da Conceiçao;
Luiz Alberto Beraldo de Moraes
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| Advisor: | Alessandra Lopes de Oliveira |
| Abstract | |
The aim of this work was to evaluate the Corymbia citriodora essential oil (EO) composition produced by the main Brazilian distilleries; Meneghetti and Três Barras moreover evaluate the yield, composition and biological activity of (EO) and oleoresin (OR) obtained from leaves by using supercritical fluids technology. The effects of operational conditions, pressure (P) and temperature (T), on chemical composition and yield were studied. The cut leaves showed moisture content of 7,33±1,1 and 8,66±0,5% to FMG and FTB samples, respectively. The extractions using CO2 in sub and supercritical conditions were performed in two steps. In the first step the EO was obtained. After, the operational conditions were readjusted to make the OR extraction. The P and T values were determined using a complete factorial experimental design (CFED). It was used two experimental designs, one for each step. The volatile profile of all EO, obtained by steam distillation (AV), hydrodistillation (HD) and SFE were determined using a gas chromatography coupled with mass spectrometer (GC/MS) equipment. The experiments that provide the higher yields in EO without pigments coextraction (100 bar e 60ºC, FTB=1,59% e FMG= 1,56%) and OR (220 bar e 70ºC, FTB=1,59% e FMG= 1,56%) had their antioxidant activity determined by DPPH test and β-carotene bleaching assay. The OR was also evaluated for its content of total flavonoids and total phenolics by two different methods, Prussian Blue and Folin-Ciocalteu. In the FTB sample, SFE, to the sample FTB was observed the positive influence of P on essential oil yield (p<0,05), whereas to FMG the variables P and T or its interaction do not have significantly influence in this response. The citronellal concentration (CC) had a positive influence of P to FTB sample and P x T interaction to FMG sample. To FTB, at 100 bar and 60ºC, the EO yield was similar from that obtained by HD (1,59% e 1,6±0,15%, respectively). However the citronelal concentration was higher than ( 87,6%) that obtained by the convencional method (79,5%). At the same conditions, to the FMG sample at the same conditions, the yields were 1,53 e 1,16±0,15% and the citrionelal concentration were 71,8% e 57,9% to the EO obtained by SFE and HD, respectively. OE obtained by AV from FTB and FMG showed citronellal concentrations of 79,8 e 76,6%, respectively. In this EO were identified a variety of compounds with biological activity; it was verified variations in both quantity and the quality of the compounds in each sample. The ORs obtained from FTB and FMG showed a high antioxidant capacity in both, β-carotene bleaching assay and DPPH test, with inhibition of 81,6±3,0 e 81,7±1,6% and EC50 of 18,04±0,6 e 12,6±0,4 mg/mL, respectively. Reducing capacity of OR compounds was higher in Prussian Blue method (FTB= 15,7±1,6 e FMG= 12,9±0,5 mg EAG/100g of leaves) in relation to Folin-Ciocalteu reagent (FTB=74,2±4,0 e FMG= 84,8±2,4, em mg EC/100g de folhas). Total flavonoids (FTB=26,7±3,9 e FMG=20,4±0,9, em mg EC/100g of leaves) were higher than the value of phenolic compounds obtained in Folin-Ciocalteu reagent, probably because the extract was tested crude. The results obtained suggest that by using the SFE it is possible to obtain an EO with a high citronellal concentration. OR also showed a high antioxidant capacity. The SFE technique also improve the raw material utilization by the sequencial and selective extraction of EO and OR, in relation of conventional methods. (AU) | |
| FAPESP's process: | 10/14145-2 - Composition study of the eucalyptus essential oil from Brazil and its enrichment of the key compounds using supercritical CO2 |
| Grantee: | Mirelle Dogenski |
| Support Opportunities: | Scholarships in Brazil - Master |