Extração supercrítica da polpa liofilizada de açaí (Euterpe oleracea Mart.): determinação de compostos bioativos e solubilidade

Abstract

The present study brings results related to the use of supercritical CO2 to obtain oil from the freeze-dried açaí pulp. During the period of this work, analyzes of bioactive compounds and prediction of oil solubility in supercritical CO2 were carried out in three municipalities in the state of Pará, Brazil: Anajás, Chaves and Saracá, and extractions were carried out under these conditions: 50 °C/350 bar, 60 °C/420 and 70 °C/490 bar. In this study, the levels of bioactive compounds present in the pulp before and after extraction were determined and the highest yields of oil in mass (57.06%) were obtained for the locality of Chaves. Based on the fatty acid composition, the levels of triglycerides present in the oil were predicted and the main predicted TAGs were OOO, POO, OLiO, PLiO and POP and the solubility prediction showed the same behavior of the global yields that increased as the pressure and temperature increased. Furthermore, after the extractions, there was an increase in the concentrations of bioactive compounds and in the antioxidant capacity in the lyophilized açaí pulp from all municipalities. The lyophilized pulp of the fruits of the açaí palm (Euterpe oleracea Mart.) from the three municipalities was also submitted to an evaluation of its morphological structure by the methods of Scanning Electron Microscopy (SEM) and X-ray Energy Dispersive Spectroscopy (EDS), which showed irregular shape and size of the pulp particles and presence of the chemical elements oxygen, potassium and calcium. Regarding the color parameters of the lyophilized pulp, the a* coordinate showed positive values, indicating that the samples tend to purple, the hue angle °Hue showed a certain tendency to the color range between red and purple. The results of the mineral profile showed that the minerals Ca and Mg from the pulp of the three regions studied were the minerals found in abundance, with concentrations ranging from 4951.55 μg/g to 5540.41 μg/g.