ABSTRACT
Tree nut by-products could contain a wide range of phytochemicals, natural antioxidants, which might be used as a natural source for dietary supplements. The aim of the present study was to evaluate the phenolic and sterolic composition, as well as the antioxidant and other biological activities, of hazelnut involucre (HI) extracts. Experimental designs were developed in order to select the optimum extraction conditions (solvent, temperature, time) using turbo-extraction by Ultra-Turrax for obtaining extracts rich in bioactive compounds. Qualitative and quantitative analyses were performed by LC-MS and LC-MS/MS and they revealed important amounts of individual polyphenols and phytosterols, molecules with antioxidant potential. The richest polyphenolic HI extract with the highest antioxidant activity by TEAC assay was further evaluated by other in vitro antioxidant tests (DPPH, FRAP) and enzyme inhibitory assays. Additionally, the cytotoxic and antioxidant effects of this extract on two cancerous cell lines and on normal cells were tested. This is the first study to analyze the composition of both hydrophilic and lipophilic bioactive compounds in HI extracts. Our findings reveal that this plant by-product presents strong biological activities, justifying further research, and it could be considered an inexpensive source of natural antioxidants for food, pharmaceutical, or cosmetic industry.
ABSTRACT
Eugenia involucrata, também conhecida como cerejeira-do-mato, é uma espécie nativa do sul do Brasil. O objetivo do trabalho foi otimizar um extrato das folhas de E. involucrata, empregando turbo-extração, e desenvolver uma emulsão, contendo o extrato, avaliando a atividade antimicrobiana. Para otimização do extrato foram avaliados dois fatores, determinando resíduo seco e teor de compostos fenólicos. Na elaboração da emulsão foi utilizado homogeneizador ultra turrax, e as concentrações do extrato adicionadas à emulsão foram de 0,5; 1,0; 1,5 e 2,0%. As formulações foram avaliadas frente ao pH, características visuais, tamanho de partícula e polidispersão. Para o ensaio antimicrobiano foi aplicada técnica de difusão em ágar. Por meio do planejamento fatorial 32 do Centro de Pesquisa e Processamento de Alimentos - CEPPA, considerando os fatores polaridade do solvente e tempo de extração, foi possível verificar melhores resultados com o extrato obtido em solvente etanol e tempo de extração de 3 minutos. A formulação apresentou pH ácido, sem separação de fases, variações no tamanho de gotícula, indicando sistema com distribuição heterogênea e atividade antifúngica. O sistema emulsionado desenvolvido, contendo diferentes concentrações de extrato, apresentou atividade antifúngica em todas as concentrações testadas, indicando que novos estudos podem ser realizados para otimizar a formulação desenvolvida.(AU)
Eugenia involucrata, popularly known as cerejeira-do-mato, is a native specie of brazilian south. The aim was to optimize an extract from the leaves of E. involucrata, using turbo-extraction, and developed an emulsion evaluation antimicrobial activity. Two factors were determined, time and polarity of the solvent, determining the dry residue and phenolic compounds content. Ultra turrax homogenizer was used for preparation of the emulsion and the extract concentrations added were 0.5; 1.0; 1.5 and 2%. The formulations were evaluated for pH, visual characteristics, particle size and polydispersity. The microbiological assay agar diffusion technique was applied. Using the factorial design 32 of the Center for Research and Food Processing - CRFP, considering solvent polarity (hexane, dichloromethane and ethanol 70%) and extraction time (10, 20 and 30 minutes), was possible to verify the extract obtained of 3 minutes with the ethanol solvent was the better results. The formulation showed acidic pH, without phase separation, variations in droplet size, indicating system with heterogeneous distribution and antifungal activity. The emulsified system developed with different concentrations of extract showed antifungal activity in all the concentrations tested, indicating that new studies can be carried out to optimize the developed formulation.(AU)
