AVALIAÇÃO FÍSICO-QUÍMICA DO BARU: INFLUÊNCIA DA SECAGEM DO EPICARPO E MESOCARPO E DIFERENTES MÉTODOS DE EXTRAÇÃO DO ÓLEO DA AMÊNDOA

Abstract

The Barueiro (Dipteryx alata Vogel) is one of several fruit plant species that can be found in the Savanna. The fruit produced is called Baru, internally it presents fleshy pulp with large amount of fibers that is discarded and considered as a residue. Inside it houses an almond used in traditional cooking. In recent years the society has become increasingly demanding for nutrients from food suppliers which have protective effect to the body. The aim of this study was to evaluate and quantify the levels of compounds with bioactive properties in hydroethanolic extracts of Baru bark (epicarp and mesocarp) after drying and in conventional and supercritical almond extracts. First, the bark was dried in a greenhouse with forced air circulation at temperatures of 50, 60, 70 and 80ºC. After that, the physico-chemical analyzes of pH, total soluble solids (ºBRIX) and total titratable acidity of the hydroethanolic extracts of the dried Baru bark were carried out. From the extracts the contents of phenolic compounds, tannins, flavonoids and antioxidant activity were analyzed and quantified. With the almond Baru, the conventional Soxhlet extraction was performed using hexane as a solvent and supercritical extractions was proceeded using the carbon dioxide (CO2) as fluid. It was determined which extraction method allowed higher yields, phenolic compound contents and oil protection capacity. Through the results analysis, it was possible to verify that the drying improved the soluble solids content, and reduced the pH. In this way, the samples became more acidic as the temperature increased. The temperatures of 50ºC and 80ºC, resulted in small values of bioactive compounds and antioxidant activity, due to the long periods of sample exposure and high temperatures provide the thermal components decomposition. The drying temperature that conditioned the highest potentiation of the flavonoid content and antioxidant activity occurred at 70ºC. Being an intermediate temperature, not causing the compounds thermal degradation with bioactive properties. The tannins and phenolic compounds levels did not present statistical difference according to the Tukey test at the 5% level. However, the oils obtained through the supercritical extraction presented higher yields, phenolic compounds and protection capacity when compared to the oils obtained by conventional extraction.