Ultrasound-assisted extraction and characterization of Brazil nut oil (Bertholletia excelsa)

Abstract

The Brazil nut is a highly valuable species in the Amazon, both for its economic value and for its nutritional profile. To preserve the nutritional quality of the oil extracted from these nuts, it is important to use appropriate extraction techniques. Among the options available is ultrasound-assisted extraction, which improves solvent penetration and facilitates mass transfer in ruptured cells, making it an efficient approach that preserves the quality of the final product. The aim of this study was to evaluate the changes in the physicochemical and thermal characteristics of Brazil nut oil after ultrasound treatment. Quality parameters were considered, such as acidity and saponification indices, as well as thermal-oxidative properties such as density, viscosity and thermogravimetry. The results indicated that this technique did not significantly alter the properties of the oil and, according to the thermophysical analyses, the Brazil nut oil obtained by ultrasound-assisted extraction showed characteristics similar to other vegetable oils, such as a density of 887 kg.m-3 at 20 oC and a viscosity of 32.5 mPa.s at 25 oC. The proposed method proved to be a practical, fast and economical alternative for extracting Brazil nut oil, maintaining its quality and guaranteeing consumer safety. These characteristics are essential for its application in food products such as chocolates, ice cream and bakery items, as well as its potential use in the cosmetics industry.