Abstract
Instant properties of chocolate powder such as solubility and dispersibility are important factors for the quality and consequently consumer acceptance of the final powdered beverage. With the aim of producing a novel powdered chocolate beverage with enhanced instant solubility, we studied the effect of spray drying process on the components of the chocolate powder. Spray drying of chocolate beverage formulation (complete recipe provided and protected by Domori s.r.l., Italy) was performed using a mixture of cocoa powder and sucrose 30:70 (w/w). Liquid feed was prepared by dissolving 17.5 g of powder in 100 mL of deionized water at 60 °C and mixed until complete homogenization. The solution was fed to a mini spray dryer B-290 (Büchi, Huddersfield, UK). In this work an inlet temperature of 150 °C was used. Maltodextrin concentration (0, 3.5 and 7 % w/w) and drying air flow rate (22, 27 and 32 m3/h) were varied. Powders were stored at 4 °C in closed dark vessels before analysis.
The results of full factorial design showed that operating at a drying air flow rate of 27 m3/h and a maltodextrin concentration of 3.5 % w/w, powder with solubility of 74.2 ± 6.8% and dispersibility of 58.7 ± 2.9% was achieved. At this operative condition, powder recovery yield was almost consistent with the industrial one (45.5 ± 2.5%). Therefore, spray drying presents a useful way to produce chocolate powder with better instant solubility, which can also be dissolved in less amount of water (70 mL instead of 120 mL).
