Extração e avaliação do rendimento do extrato de Stevia Rebaudiana Bertoni

• Autor(a) principal: Medeiros, Paulo Joadi Guerra Lima de
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/38929
• topic: Adoçantes; Stevia rebaudiana Bertoni; Glicosídeos de esteviol; High Performance Liquid Chromatography; Rendimentos globais mássicos; Extrações convencionais; Engenharias.

In the quest for a better quality of life, people have sought to consume healthier foods. Thus, low calorie sweeteners prepared from natural sources are highlighted and are used as substituents of sugar, one of those responsible for nutritional and health problems. Among the natural sweeteners, the steviol glycosides present in the leaves of the Stevia rebaudiana Bertoni plant, from the northeast of Paraguay. In view of this, the general objective of this work was to evaluate the mass global yields of simple and sequential conventional extractions with polar and nonpolar solvents, also analyzing the influence of polarity on the yields. In addition, analyzing the extract samples and the Stevia commercial sweetener sample in High Performance Liquid Chromatography (HPLC), comparing the concentration and content of the identified major components. For this, the extractions were carried out with 20 g of dry leaves sample of Stevia rebaudiana Bertoni soaked in 200 mL of solvent, at 25 ºC, during 24 h under agitation of 200 rpm. The results of the total yield of the simple extractions showed values of 6.73% with the solvent ethanol; 17.49% with ethanol:water (80:20 v/v); 17.58% with water; 17.30% with methanol; and methanol:water (80:20 v / v) solvent mixture had the highest yield of 24.70%. The yields for the sequential extraction were 0.87% with hexane, 2.96% with dichloromethane, 1.39% with ethyl acetate and the highest yield was obtained with methanol, with the value 19.09%. From the chromatograms, it was found that the concentrations of the major components found in the extract samples were higher than the concentrations of the same components in the commercial sweetener sample, with the highest concentrations found in the extract sample of the methanol:water mixture considering the simple extractions, and in the methanol sample, considering the sequential extraction. For the percentage of components in the samples, components 1 and 2 presented in the extraction samples contents higher than the content in the commercial samples. However, component 3 presented the highest percentage in the commercial sample, while the extraction samples presented lower contents.