Master's Dissertation
DOI
https://doi.org/10.11606/D.74.2018.tde-23102018-111708
Document
Author
Full name
Gabriela Marques Bittencourt
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
Pirassununga, 2018
Supervisor
Committee
Oliveira, Alessandra Lopes de (President)
Comunian, Talita Aline
Gonçalves, Cintia Bernardo
Melo, Mariza Pires de
Title in Portuguese
Avaliação da atividade antioxidante e antimicrobiana de extratos de araçá (Psidium grandifolium Mart. ex DC.) obtidos por líquido pressurizado (PLE) e por fluido supercrítico (SFE)
Keywords in Portuguese
Psidium cinereum
Atividades antioxidante e antimicrobiana
Caracterização de voláteis
CO2 supercrítico
Composição mineral
Extração com etanol pressurizado
Abstract in Portuguese
O araçá é um fruto, pertencente à espécie Psidium grandifolium Mart. ex DC, nativo da mata atlântica brasileira pouco caracterizado pela literatura ciêntífica. Esta pesquisa visou estudar o rendimento de extração e avaliar as atividades antioxidante e antimicrobiana do óleo essencial de araçá obtido por extração com dióxido de carbono supercrítico (SFE) e dos diferentes extratos obtidos por extração com etanol pressurizado (PLE) seguindo um delineamento composto central rotacional com temperatura e tempo estático como variáveis independentes estudadas. Avaliou-se também o perfil de voláteis do óleo essencial, o teor de compostos fenólicos totais dos extratos etanólicos e as alterações causadas na matriz vegetal por diferentes processos de extração. Com a SFE conseguiu-se extrair toda a fração lipídica do fruto (2,33% ± 0,04.10-2%), a análise dos compostos voláteis do óleo essencial obtido permitiu inferir que este possui diversos compostos com potencial bioativo tais como E-cariofileno (17.56%), α-humuleno (16,26%) e β-sesquifelandreno (14.27%); porém este óleo essencial não apresentou atividade antioxidante relevante. O extrato etanólico com maior rendimento (17, 49%) foi obtido a 74 °C por 6 min, mesma condição em que obteve-se a maior atividade antioxidante (EC50 = 6,37 mg/mL), porém o maior teor de compostos fenólicos totais (136,95 mg EGA/100 g de massa seca) foi obtido quando aplicou-se 60°C por 9 min. Em relação à atividade antimicrobiana, tanto os extratos obtidos por PLE quanto por SFE apresentaram atividade contra cepas de P. aeruginosa, S. aureus e B. cereus, somente extratos etanólicos apresentaram atividade contra cepas de L. monocytogenes e nenhum dos extratos apresentaram atividade contra cepas de B. subtilis, E. coli e Salmonella. Em ambos os extratos foi possível identificar compostos com potencial aplicação farmacológica. O estudo de processos de extração que envolvam inovação tecnológica na obtenção extratos com atividade biológica visa contribuir com o extrativismo consciente ou estimular o plantio em maior escala de mais um fruto tropical empregado na medicina popular brasileira.
Title in English
Evaluation of the antioxidante and atimicrobial activity of araçá extracts (Psidium grandifolium Mart. ex DC.) obtained by pressurized liquid extraction (PLE) and supercritical fluid extraction (SFE)
Keywords in English
Psidium cinereum
Antioxidant and antimicrobial activities
Mineral composition
Pressurized ethanol extraction
supercritical CO2
Volatile characterization
Abstract in English
The araçá is a fruit, belonging to the species Psidium grandifolium Mart. ex DC, native of the Brazilian Atlantic Forest, is not largely characterized by the scientific literature. This research work aimed to study the extraction yield and to evaluate the antioxidant and antimicrobial activities of the araçá essential oil obtained by supercritical carbon dioxide extraction (SFE) and the different extracts obtained by pressurized ethanol extraction (PLE) following a central composite design with temperature and static time as independent variables studied. It was also evaluated the volatile profile of the essential oil, the content of total phenolic compounds of the ethanolic extracts and the changes caused in the vegetal matrix by different extraction processes. SFE was able to extract the whole lipid fraction of the fruit (2.33% ± 0.04.10-2%), the analysis of the volatile compounds of the essential oil obtained allowed to infer that it has several compounds with bioactive potential such as E-caryophyllene (17.56%), α-humulene (16.26%) and β-sesquipelandene (14.27%); but this essential oil had no relevant antioxidant activity. The highest ethanolic extract (17, 49%) was obtained at 74 °C for 6 min, the same condition in which the highest antioxidant activity was obtained (EC50 = 6.37 mg/mL), but the higher content of total phenolics contente (136.95 mg EGA / 100 g dry mass) was obtained when 60 °C was applied for 9 min. In relation to the antimicrobial activity, both extracts obtained by PLE and SFE showed activity against P. aeruginosa, S. aureus and B. cereus strains, only ethanolic extracts showed activity against L. monocytogenes strains and none of the extracts presented activity against B. subtilis, E. coli and Salmonella strains. In both extracts it was possible to identify compounds with potential pharmacological application. The study of extraction processes that involve technological innovation in obtaining extracts with biological activity aims to contribute to the conscious extraction or stimulate the larger scale cultivation of another tropical fruit used in Brazilian popular medicine.
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Publishing Date
2018-11-01