Evaluation of the drying parameters of soursop pulp powder obtained by drying in a spray dryer

Abstract Soursop pulp is a widely consumed product in Brazil and its dehydration by spray drying has been shown to be a relevant alternative for the exploitation of surplus production. Thus the objective of this research was to establish the best operational conditions to dry soursop pulp in a spray dryer to obtain the powder, using a central composite rotational design (CCRD), the independent variables being the maltodextrin concentration and the drying air temperature. Significant negative linear and quadratic effects (p < 0.05) were found for the maltodextrin concentration and drying air temperature on the moisture content of the powdered soursop pulp. Although the model did not adjust to the hygroscopicity and yield parameters, the process conditions could be established using the means test. Considering the use of low temperatures and lower maltodextrin concentrations, the use of a drying temperature of 169 °C and 17% (w/w) of maltodextrin as the drying aid was recommended. The use of such conditions resulted in a product with low moisture content and water activity, classified as slightly hygroscopic, caking sensitive and that presents a microstructure with spherical shape, different sizes and smooth and uniform surface.