Extração de compostos bioativos e efeitos da secagem em frutos verdes e maduros de erva-mate

Abstract

Ilex paraguariensis A. St. Hil, popularly known as yerba mate, is a tree from South America that produces leaves, flowers and fruits. The consumption of leaves and stems has cultural meaning, usually prepared through a stimulating drink called such as “mate” or “chimarrão”. The fruits, however, are considered by-products, but their demand may grow according to future discoveries related to their composition and functional properties. In view of the above, the present study aimed to evaluate the extraction kinetics of phenolic compounds from ripe and unripe yerba mate fruits through magnetic and ultrasound-assisted stirring. Two kinetic models were chosen to represent the extraction process: non-linear pseudo-first order and non-linear pseudo-second order. Ripe fruits showed higher concentrations of phenolic compounds and the magnetic stirring method resulted in higher concentrations (maximum of 379 μg gallic acid g-1 dry mass). The pseudo-second order kinetic model showed the best adjust in all extractions, with R2 > 0.97. The optimal extraction time was situated in a range between 25 and 40 minutes.