Extração de compostos bioativos das folhas de araçá vermelho (Psidium cattleianum Sabine) utilizando as técnicas de extração supercrítica e assistida por ultrassom

Abstract

Psidium cattleianum Sabine (red araçá), typical of South America tree belongs to the family Myrtaceae, the same family of guava, uvaia, pitanga and other plants. Some literature studies indicate that its extracts are rich in bioactive compounds with pharmaceutical interest. The present work aims to study non - conventional and conventional methods of obtaining bioactive extracts of red araçá. Were evaluated the pressure and temperature factors for supercritical extraction and the factors of power, temperature and ratio between leaf mass and volume of solvent for ultrasonic assisted extraction as a response variable the yield. After the material was dried and ground, the supercritical extraction was conducted at temperatures of 35, 45 and 55 °C and pressures of 140, 170 and 200 bar, both with a fixed flow of 2.0x10-3 kg.min-1. The following variables were evaluated in the ultrasonic assisted extraction: temperature (40, 50 and 60 ° C), potency (20, 60 and 100%) and ratio between leaf mass and solvent volume (1:10, 1:15 and 1:20 w/v). For the extraction by the soxhlet method, the yield was found to be 3.59%, the greatest one found. For the dynamic maceration the yield was 0.951%, at the temperature of 40 °C, rotation of 100 RPM and mass/solvent ratio of 1:20 for a time of 80 minutes, reaching the balance in the 40 minutes. In the supercritical extraction the best result was at 200 bar and 55 °C obtaining a yield of 0.858%. In the ultrasonic assisted extraction the yield of 2.676% was obtained at a temperature of 40 °C, at 100% potency, and at a mass/solvent ratio of 1:20 for a time of 5 minutes. The results of supercritical extraction in the statistical analysis it was found that any of the variables studied had no significant effect on the yield, while the UAE the variable power ratio and mass / solvent had significant effect. For mathematical modeling of the supercritical fluid extraction, the sovová and second order models satisfactorily represented the extraction kinetics under all conditions investigated. The extracts were characterized chemically by GC-MS presenting as main compounds Vitamin E, Eudesmol and Squalene. Vitamin E had the highest concentration with 53.42% and quality 99 in supercritical fluid extraction at 55 ° C and 200 bar. For the antioxidant activity of DPPH method the extract obtained with the supercritical fluid extraction had the best efficient concentration the 14,182 in the 140 bar and 55 °C condition, because it required a lower concentration to inhibit 50% of the DPPH radical.