Produção e armazenamento de formulações de leite de cabra e polpa de umbu-cajá.

Abstract

This work had as objective to dehydrate, in spray dryer, emulsions composed by goat milk (80%) and umbu-cajá pulp (20%) with fixed concentrations and two different maltodextrin concentrations (10 and 15%). The whole umbu-cajá pulp and the emulsions were characterized according to the pH, soluble solids (°Brix), ascorbic acid, titratable acidity, reducers sugar and ashes, while the goat milk was characterized according to the acidity, fat, not fat solids, density, lactose, ashes, pH and soluble solids. The apparent viscosities of the whole umbu-cajá pulp and of the emulsions with 10 and 15% of maltodextrin were determined through the viscosimeter Brookfield. The moisture adsorption isotherms of the powders, at the temperatures of 20, 25, 30, 35 and 40oC, were determined through the Thermoconstant Novasina equipment, and the GAB, Peleg and Oswin models were fitted to the experimental curves. The physical-chemistries characteristics of the powders were evaluated, during six months of storage, at room temperature, in two types of laminate packing. It was observed that density, ashes, titratable acidity and lactose of the goat milk are according to the quality patterns established by the legislation, except the not fat solids. The values of the physical-chemical characterization of the umbu-cajá pulp were 89,55% for the moisture; 10,45% for total solids; 2,52 for the pH; 12,00 °Brix for soluble solids; 0,41% for ashes; 13,53 mg/100 g for ascorbic acid; 2,04% of citric acid for the titratable acidity and 7,22% of glucose for reducers sugar. The values of the physical-chemistry characterization were statistically different among the emulsions with 10 and 15% of maltodextrin, except for the ashes. The apparent viscosities decreased with the increase of the rotation speed, for all the used temperatures. Peleg's model was the one which was better fitted to the moisture adsorption isotherms of the powders samples. During the storage of the powders, the moisture and the pH presented increase tendency with the time of storage, the titratable acidity presented tendency of stability; the ascorbic acid, the reducers sugar and the color parameters (brightness, redness and yellowness) showed reduction tendency with the time of storage.