Experimental optimization of cape gooseberry pulp (Physalis peruviana) formulation to improve its processing by spray drying

Background: In Colombia, the Cape gooseberry fruit (Physalis peruviana) is identified as a promising export fruit, so improving its processing is contributing to greater competitiveness of the chain. Objectives: The aim of this study was to optimize suspension of cape gooseberry pulp mixed with gum arabic (GA) and maltodextrin (MD) with the purpose of being used in spray drying. Methods: The optimization was performed using a central composite design with response surface of two factors (MD and GA) and response variables (density, ° Brix, water activity (aw), pH, and rheological parameters). Results: The rheological characterization of the suspensions showed a shear thinning behavior with yield stress (Herschel-Bulkley Model). The results indicated that best suspension to be used in spray drying would be formulated with MD (24%) and GA (0%) showing a rheological response of Herschel-Bulkley fluid with consistency index (K=0.119±0.017 Pa-sn), power index (n=0.75±0.03) and yield stress (τo=0,092±0,069 Pa). To the optimized condition, the results for the physicochemical properties were density (1.167 ± 0.005 g/mL), °Brix (35.5±0.5), aw (0.974±0.002). Additionally, the pH and τo of Herschel Bulkley model was not statistically significant (p>0.05) in the suspension formulation. Conclusions: The experimental optimization is an important tool that allowed us to obtain a formulation of gooseberry with MD and GA suitable for spray drying, representing a saving in time and money for research and industry.