Hygroscopic behavior of bacuri powders

Abstract

Abstract The objective of this work was to evaluate the hygroscopic behavior and physical properties of powders from bacuri pulp freeze-dried with different drying adjuvants. Three samples were prepared by adding the maltodextrin, gum Arabic, and albumin adjuvants, at a concentration of 20% (w/w), to the pulp. The powders were analyzed for moisture content, hygroscopicity, and particle morphology. The adsorption isotherms were obtained using the models of Brunauer-Emmett-Teller (BET), Guggehneim-Anderson-de Bôer (GAB), Henderson, and Oswin at the temperatures of 25 and 40ºC. Moisture contents ranged from 2.12 to 2.90%, and the lowest value was observed for the powder containing albumin. Hygroscopicity varied from 3.64 to 6.02%, with the lowest value for the powder containing maltodextrin. The powder particles showed non-spherical and irregular shapes, being more agglomerated in the powder with maltodextrin. For the isotherm, the best fit was obtained with the BET model and a type-III behavior was observed, which is typical of foods rich in soluble sugars. Therefore, the adjuvants contribute to the physicochemical properties of the powders, making them less hygroscopic and with irregular-shaped particles.

Keywords

• adjuvants
• adsorption
• drying
• moisture content
• tropical fruits