Estudo para a otimização da extração de compostos fenólicos presentes na erva mate (Ilex paraguariensis) utilizando líquidos iônicos

Abstract

Extracts of plant tissues have been presented a rich source in compounds considered beneficial for the health of the human being. The herb mate is a plant that has in its composition high concentration of phenolic compounds that act as antioxidants. Currently, consumer interest in food products that have a high concentration of phenolic compounds has been increasing, resulting in research that seeks to improve the extraction methodologies of these components. Thus, the purpose of this work was to evaluate the extraction efficiency of phenolic compounds present in mate grass, using ionic liquids as solvent. The herb mate obtained in the city of Laranjeiras do Sul - PR was sanitized and dried in an oven at 30 ºC, crushed and separated in different granulometries. Initially, preliminary extraction experiments with ionic liquids (2-hydroxyethanolaminine acetate, 2-hydroxydiethanolamineamine and choline chloride) and ethanol were carried out in order to evaluate the extraction efficiency of phenolic compounds from each solvent. Then, a central rotational compound (DCCR) was used to verify the influence of temperature, grain size and solvent concentration on the extraction of phenolic compounds from mate grass, using ethyl alcohol and 2-hydroxyethanolamine acetate. Finally, the kinetic study with the best experimental design conditions was developed to identify the time required for solid liquid extraction to enter into equilibrium. The results obtained in the preliminary tests showed that ethyl alcohol was the solvent that had the lowest extraction efficiency and that 2-hydroxyethanolamine acetate was the solvent that most extracted phenolic compounds, approximately 117% more than ethyl alcohol. In the experimental design using ethanol, it was found that at higher temperatures and in a solvent concentration range between 30 and 70%, there was a greater extraction of phenolic compounds. While in the experimental design with 2-hydroxyethanolamine acetate, the extraction tended to be more efficient using high ionic liquid concentrations, both in low and high temperatures. The kinetic study showed that extraction of phenolic compounds from mate grass using 2- hydroxyethanolamine acetate is rapid and that the equilibrium time was approximately 5 hours.