Freeze-dried bacuri pulp powder: the eff ect of adjuvants

Abstract

The aim of this study was to evaluate the effect of the drying adjuvants maltodextrin, gum Arabic and albumin on the physical and physicochemical characteristics of freeze-dried bacuri pulp powder. The adjuvants were added to the pulp at a concentration of 20% (w/w), giving three samples that were dehydrated in a freeze-dryer. The samples were analysed for moisture content, colour using the CIELab scale, phenolic compounds, hygroscopicity, particle morphology and density. The fluidity of the powders was evaluated using the Carr index and Hausner ratio. The moisture ranged from 2.33% to 2.76%, the powder containing albumin having the lowest moisture content (p < 0.05). A difference (p < 0.05) was seen in the colour parameters of the samples, except for luminosity in the samples containing maltodextrin or albumin. The level of phenolic compounds ranged from 183.22 to 386.90 mg GAE/100 g of solids, with the sample containing albumin again showing the lowest value (p < 0.05). The hygroscopicity of the powders ranged from 6.22% to 6.92%, the densities ranged from 287.9 to 433.1 kg/m³, and the wall friction angle from 12.2° to 13.55°. The Carr index and Hausner ratio varied from 23.21% to 25.80% and 1.30 to 1.34, respectively.The bacuri pulp powder was classified as having acceptable fluidity regardless of the adjuvant; however, the adjuvants had an effect on particle morphology and on the composition of the powder.