Extração sequencial de óleo e proteínas da amêndoa do pequi (caryocar brasiliense camb.) assistida ou não por ultrassom

Abstract

The pequi (Caryocar brasiliense Camb.), a native fruit of the Brazilian cerrado, has the potential for full utilization of all its parts, including the peel, pulp, and kernel, the latter being rich in lipids and proteins. Considering its economic and nutritional importance, and the growing demand for plant-based products, the pequi in its entirety shows great potential for the exploitation of its compounds. This project aims to evaluate the use of more sustainable technologies for the sequential extraction of oil and proteins from the pequi kernel, using “green” solvents, with and without the aid of ultrasound, in the oil extraction step. The pequi kernel was subjected to two oil extraction processes using ethanol: one with agitation, without ultrasound, and the other with ultrasound assistance. In the ultrasound treatment, the effects of amplitude and sonication time on the oil extraction yield and the protein concentration obtained in the sequential extraction of the residue were evaluated. The residue resulting from the oil extraction was subjected to protein extraction using two solvents (water and phosphate buffer solution) at pH levels ranging from 2 to 10. The results showed that ultrasound, with 27% amplitude and 18 minutes, achieved the highest oil extraction yield (45.21%); lower than the oil extraction yield with ethanol (59.86%) and hexane (97.78%) without the use of ultrasound. In the sequential extraction of protein from the residue, the use of ultrasound (in the oil extraction step) resulted in lower protein concentrations compared to the protein extraction from residues obtained without the application of ultrasound. The phosphate buffer solution at pH 7 was the most effective for extracting proteins from the pequi kernel. The pequi kernel is a source of oil, proteins, and energy value, and the use of ultrasound with ethanol as a solvent contributes to an efficient extraction process of these compounds. It was concluded that the sequential extraction of oil and proteins from the pequi kernel, assisted or not by ultrasound, is promising.