Determinação da atividade antioxidante in vitro e in vivo em bebidas de café: influência do tipo de extração

• Ano de defesa: 2014
• Autor(a) principal: Daniel Mansur Rabelo
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Ciência de Alimentos; Cafe; Café Análise; Extração (Quimica); Antioxidantes
• Link de acesso: http://hdl.handle.net/1843/BUBD-9XTH2X

Coffee, fruit of the coffee tree( genus Coffea ) , contains seeds that when roasted and ground generate one of the most consumed beverages in the world. To coffee consumption are attributed many health benefits, most of them linked to their antioxidant properties. The components of coffee linked to this activity are mainly polyphenols , caffeine and melanoidins . Several factors such as the type of crop, the species of coffee used , the degree of roasting and brewing method (the extraction form) influence on the chemical composition and biological activity of coffee. As extraction form, it can used infusion followed by filtration, decoction without filtration or pressure, using espresso machines . The antioxidant activity basically consists in reversing the process of oxidative stress, which occurs when more free radicals are generated than eliminated from the body. Thus, this study aimed to evaluate the antioxidant activity in vitro and in vivo of coffee beverages obtained from different types of extraction. For this, were prepared from the same sample of roasted and ground coffee drinks at concentration of 10 g/L in the forms of filtered ( infusion), boiled ( decoction ) and espresso (pressure) and were performed antioxidant activity assays in vitro ( DPPH and ABTS ) and in vivo using healthy animals subjected to a daily dosage equivalent to drink 350 mL for an adult of 70 kg, in whose livers were determined the activities of catalase and glutathione reductase and the extent of peroxidation by TBARS, beyond the determination of some biochemical parameters in blood. In vitro, boiled coffee had lower activity than the others , and the espresso coffee showed the highest activity in the DPPH assay (obtained values to CE50% , expressed ing/mL: 30,53 ± 1,72 for espresso, 36,96 ± 1,20 for filtered and 66,00 ± 2,02 for the boiled coffee), but espresso and filtered showed no significant difference (p<0,05) were found between control and treatments and between the treatments each other. As there was significant difference of in vitro antioxidant activities and there is antioxidant activity in vivo assigned to the coffee in other studies, it is suspected that the exposure time may have been insufficient or could be induced oxidative stress in the animals, in order to get a better response. Therefore, further studies will be carried out to confirm the results obtained in this work.