A carregar...
Publicação
Estudo do óleo de ximenia americana L. de produção artesanal angolana: avaliação das propriedades químicas e biológicas
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 2 MB | Adobe PDF |
Autores
Orientador(es)
Resumo(s)
A Ximénia americana L. é uma planta cosmopolita tropical, vulgarmente encontrada em África, Índia, Nova Zelândia, América Central e América do Sul. Em Angola é amplamente utilizada na medicina tradicional, no combate da malária e também na cicatrização de feridas causadas pela sífilis. No entanto, a sua utilização mais frequente consiste na aplicação do óleo das sementes como emoliente, condicionador, amaciante de pele, tratamentos do cabelo e para untar o corpo. O óleo das sementes da Ximenia americana L., é utilizado em Angola como cosmético alternativo pelas populações indígenas e também pela grande maioria das populações das grandes cidades. O presente estudo teve como objetivo caraterizar e avaliar o óleo obtido das sementes da X. americana L., extraído, usando diferentes metodologias de extração, com a mesma variedade de sementes do município da Bibala, com a finalidade de propor uma utilização mais nobre deste produto. Foram utilizados métodos clássicos (extração com Soxhlet) e métodos não clássicos (extração pseudoartesanal) na extração do óleo de sementes desta planta O uso de diferentes métodos de extração permitiu comparar a qualidade do óleo extraído, com a do óleo proveniente de Angola, obtido pelo método artesanal. As diferentes amostras foram caracterizadas através dos seguintes parâmetros: densidade, índice de saponificação, índice de acidez, massa molecular relativa, índice de peróxido, índice de iodo, viscosidade, espectroscopia de UV-Vis e de 1H RMN. Foram analisadas ainda, por meio de diferentes técnicas analíticas, como: TLC e CG-EM. A extração do óleo pelo método pseudoartesanal foi a que produziu menor rendimento em óleo bruto com 9,72 ± 0,19% (m/m), enquanto a extração com solvente orgânico utilizando o Soxhlet mostrou ser o melhor método de extração para as sementes da Ximenia americana, apresentando o maior rendimento de 61,78 ± 0,53% (m/m). Porém, quanto aos resultados obtidos na caracterização das três amostras de óleos, verificou-se que os mesmos apresentavam diferenças entre si em quase todas as análises realizadas. A maior diferença foi observada na determinação da viscosidade e na análise da composição por CG-EM que varia conforme o processo de extração do óleo das sementes. O óleo produzido artesanalmente, proveniente de Angola mostrou ser eficaz e de boa qualidade para a utilização como cosmético, quando comparado com os dois extraídos no laboratório que apresentaram resultados equivalentes. Deve-se melhorar o método de extração, indicando que se pode produzir óleo de sementes de Ximenia americana, extraído com solvente orgânico, com maior rendimento e com qualidade equivalente ao óleo extraído artesanalmente. Relativamente à densidade do óleo e à sua dependência com a temperatura, o óleo pareceu estável o que estaria de acordo com o baixo valor do índice de peróxido, de 30 meq de O2/kg. O valor de índice de acidez situa-se na gama de 0,476 a 2,588 mg de KOH/g. O índice de iodo encontrado foi bastante alto na gama de 124,51 a 281,51 gI2/100g.
Ximenia americana L. is a tropical cosmopolitan plant commonly found in Africa, India, New Zealand, Central and South America. In Angola it is widely used in traditional medicine against malaria and also to heal wounds caused by syphilis. However, is major use is the application of the oil obtained from the seeds as emollient, conditioner, skin softener and in hair treatments and to oint the body. The oil of the seeds of Ximenia americana L., is used in Angola as an alternative cosmetic by the indigenous populations and also by the great majority of the populations of the big cities. The present study aimed to characterize the oil obtained from the seeds of Ximenia americana L., extracted using different extraction methodologies from the same variety of seeds of the Bibala municipality. Classical methods (Soxhlet extraction) and non - classical methods (pseudoartesanal extraction) were used to extract the seed oil from Ximenia americana. The use of different methods of oil extraction in the laboratory allowed to compare the quality of these oil with that from Angola, extracted by the artisanal method. The different samples were characterized by the following parameters: density, saponification index, acid number, relative molecular mass, peroxide index, iodine number, viscosity a, and UV-Vis and 1H NMR spectroscopy. Different analytical techniques, such as: TLC and CG-MS were also used. The extraction of the oil by the pseudoartesanal method yielded the lowest yield in crude oil with 9.72 ± 0.19% (m / m), while the organic solvent extraction used the Soxhlet showed to be the best extraction method for Ximenia americana, with the highest yield of 61.78 ± 0.53% (m / m). However, with respect to the results obtained in the characterization of the three oil samples, it was verified that they presented differences among themselves in almost all analyzes. The greatest difference was observed in the determination of the viscosity and in the analysis of the composition by GC-MS that varies according to the process of extraction of the oil of the seeds. Handmade oil from Angola proved to be efficient and of good quality for its use as a cosmetic when compared to the two extracted in the laboratory that presented equivalent results. The extraction method should be improved, indicating that it is possible to produce Ximenia americana seed oil, extracted with organic solvent, with higher yield and with equivalent quality to the oil extracted by local populations. The density of the oil depends on temperature. The oil appeared stable as deduced from its low peroxide value of 30 meq O 2 / kg. The acid value is in the range of 0.476 to 2.588 mg KOH / g. The iodine content was quite high in the range of 124.51 to 281.51 gI 2 / 100g.
Ximenia americana L. is a tropical cosmopolitan plant commonly found in Africa, India, New Zealand, Central and South America. In Angola it is widely used in traditional medicine against malaria and also to heal wounds caused by syphilis. However, is major use is the application of the oil obtained from the seeds as emollient, conditioner, skin softener and in hair treatments and to oint the body. The oil of the seeds of Ximenia americana L., is used in Angola as an alternative cosmetic by the indigenous populations and also by the great majority of the populations of the big cities. The present study aimed to characterize the oil obtained from the seeds of Ximenia americana L., extracted using different extraction methodologies from the same variety of seeds of the Bibala municipality. Classical methods (Soxhlet extraction) and non - classical methods (pseudoartesanal extraction) were used to extract the seed oil from Ximenia americana. The use of different methods of oil extraction in the laboratory allowed to compare the quality of these oil with that from Angola, extracted by the artisanal method. The different samples were characterized by the following parameters: density, saponification index, acid number, relative molecular mass, peroxide index, iodine number, viscosity a, and UV-Vis and 1H NMR spectroscopy. Different analytical techniques, such as: TLC and CG-MS were also used. The extraction of the oil by the pseudoartesanal method yielded the lowest yield in crude oil with 9.72 ± 0.19% (m / m), while the organic solvent extraction used the Soxhlet showed to be the best extraction method for Ximenia americana, with the highest yield of 61.78 ± 0.53% (m / m). However, with respect to the results obtained in the characterization of the three oil samples, it was verified that they presented differences among themselves in almost all analyzes. The greatest difference was observed in the determination of the viscosity and in the analysis of the composition by GC-MS that varies according to the process of extraction of the oil of the seeds. Handmade oil from Angola proved to be efficient and of good quality for its use as a cosmetic when compared to the two extracted in the laboratory that presented equivalent results. The extraction method should be improved, indicating that it is possible to produce Ximenia americana seed oil, extracted with organic solvent, with higher yield and with equivalent quality to the oil extracted by local populations. The density of the oil depends on temperature. The oil appeared stable as deduced from its low peroxide value of 30 meq O 2 / kg. The acid value is in the range of 0.476 to 2.588 mg KOH / g. The iodine content was quite high in the range of 124.51 to 281.51 gI 2 / 100g.
Descrição
Tese de mestrado, Química (Química), Universidade de Lisboa, Faculdade de Ciências, 2017
Palavras-chave
Ximenia americana Uso tradicional Extração Viscosidade Densidade do óleo das sementes Teses de mestrado - 2017