Spray Drying of Pequi Pulp: Process Performance and Physicochemical and Nutritional Properties of the Powdered Pulp

Abstract

The objective of this work was to optimize the spray drying of pequi pulp using maltodextrin as carrier agent and Tween 80 as surfactant agent. A central composite rotatable design was used to evaluate the influence of inlet air temperature (140 to 200°C), maltodextrin (15 to 30%) and surfactant (0 to 5%) concentration on the process performance and physicochemical and nutritional properties of the dried powdered pulp. The dependent variables were process yield (27.4 - 51.7%), outlet air temperature (106.5 - 135°C), energetic efficiency (29.9 - 44.8%), moisture content (0.25 - 1.43%), water activity (0.09 to 0.21), hygroscopicity (9.1 - 12.1 g adsorbed moisture/100g dry matter), vitamin C content (129.8 - 303.0 mg/g solids pequi) and total carotenoids content (8.2 - 94.9 mg carotenoids/g solids pequi). The spray drying of pequi pulp was optimized for maximum vitamin C and total carotenoids content using response surface methodology, which were attained at 152°C, surfactant concentration of 1% and maltodextrin concentration of 18%. The characterization of the pequi pulp powder obtained at the optimized condition evaluating the particles sizes, bulk density and porosity. The morphology showed spherical and smooth particles with several sizes.