Avaliação de diferentes métodos de extração como estratégia para melhorar a atividade antioxidante de extratosobtidos de resíduos de casca de café

Abstract

Due to the intense agro-industrial activity in Brazil, the sector was responsible for 27% of PIB in 2020, and large volumes of biomass are generating large volumes of biomass as one of the direct consequences. Currently part of the biomass is intended to generate energy through burning in boilers, can be used in biogas and composting plants to assist in soil recovery. However, the shells, seeds, woody, and organic materials have many nutrients that can be extracted for use in the pharmaceutical, food and cosmetic industries. The south of Minas Gerais is responsible for a large part of the coffee produced in Brazil, and after its processing to obtain coffee beans, the shells are underused or discarded generating a negative impact on the environment. Many studies indicate that coffee hulls could be used in various ways, such as animal feed, livestock, composting, biofuels, adsorbent production, among others. In coffee hulls there are phenolic compounds such as chlorogenic acid (GCA), which is considered one of the main gifts in coffee. The selected extraction method is a very important variable because it influences the production of these compounds, the content and profile of substances. The objective of this work was the evaluation of 9 extraction approaches using classic emerging techniques such as extraction using ethanol and acetone solvents, as well as techniques such as the use of ultrasound, autoclave and hydrolytic enzymes and 2 two different particle sizes (912 µm and >295 µm) to obtain extracts with high antioxidant activity. After obtaining the extracts, analyzes of total phenolic compounds, antioxidant activity by DPPH, FRAP and ABTS were carried out and the results were evaluated using the Randomized Block Design methodology. After analyzing the results, the effect of the influence of granulometry was significant only for the concentration of phenolic compounds, in addition, the enzyme-assisted extraction method (Viscozyme) and using thermal treatment (autoclave - 15min and 30 min) were the most effective for obtaining an extract with greater antioxidant activity, indicating that the use of extraction methods that are less aggressive to the environment are efficient and that the residues are promising sources of. antioxidant compounds.