PROPRIEDADES NUTRICIONAIS, FÍSICAS, QUÍMICAS E TECNOLÓGICAS FUNCIONAIS DAS FARINHAS DE BARU (Dipteryx alata Vogel) EM FUNÇÃO DE DIFERENTES CONDIÇÕES DE SECAGEM DO FRUTO

Abstract

The baru (Dipteryx alata Vogel) is a tree species, native from cerrado, produces fruits with fleshy pulp with the presence of single almonds inside. Due to the growing demand for nutritious and safe food, and the importance of the valorization of native species of the Cerrado, the present study was carried out with the objective of evaluating the drying effect of the baru fruit on the nutritional, physical, chemical and functional technological characteristics of epicarp and mesocarp flour, and kernel flour, heat-free fruits and fruits submitted to different drying conditions (40, 60, 80, 100 ºC in a forced circulation oven). There were evaluated the water content by the gravimetric method, the Kjeldhal method, ashes, by burning in muffle, lipids in Soxhlet apparatus, the energy value by the sum of Atwater conversion factors, total carbohydrates by difference calculation, pH, acidity by titration, total soluble solids (oBrix) using refractometer, grain size and apparent specific mass, color, mineral content, total phenolic compounds, antioxidant capacity, total flavonoids and carotenoids, microstructural analysis, (water, milk and oil) and solubility indices (water and milk), emulsifying activity, emulsion stability, foamability and foam stability. Drying resulted in the reduction of the pH, acidity, lipids and soluble solids of the epicarp and mesocarp flours of baru (FEMB) and baru kernel meal (FAB) compared to the control (FEMBCT and FABCT) samples. The FEMB and FAB samples presented significant levels of zinc, copper, potassium, calcium and phosphorus. Drying provided greater availability of phenolic compounds, higher antioxidant activity and flavonoid content in FEMB from dried fruits at higher temperatures. However, the bioactive compounds of the FAB food matrix presented an inverse behavior. The total phenolics, antioxidant activity, flavonoids and carotenoids were degraded. The results of the FT-IR analysis show nutrient loss. The thermal treatments of the fruits caused alterations in the color of the baru flour (FEMB and FAB), causing the darkening of the samples, reducing the values of water absorption index in milk, water solubility index and milk in FEMB. Regarding particle size, the samples dried at higher temperatures (80 and 100 ºC) presented higher percentage of particles smaller than 0.125 mm. The drying of the fruits caused alterations in the microstructure of the flour. The gelatinization of the starch granules, shrinkage and reduction of the pores of the FEMB and FAB fibers were observed at elevated temperatures. The FEMB60 and FAB80 samples showed the highest values of foamability and foam stability, FEMB60 and FAB100 samples exhibited higher values of emulsifying activity and emulsion stability.