Optimization of the foam mat drying process for production of cocoa powder enriched with peppermint extract

The potential of the foam mat drying process was explored for production of cocoa powder enriched with peppermint extract. The aim of this work was to develop and optimize a foam mat drying process in order to produce cocoa powders with optimal physical and chemical properties and good sensory acceptance. The egg white content, peppermint extract content and the mixing time were used as independent variables in the Response Surface Methodology (RSM) optimization in combination with the Box-Behnken factorial experiment design. Foam properties (stability and density), powder physical properties (particle size, bulk density, flow properties, reconstitution) total polyphenolic content (TPC), antioxidant capacity (AOC) and sensory properties were used as responses. Based on the optimization results, the highest TPC and antioxidant activity were achieved at 25 g/kg of the added peppermint extract, while among sensory properties only odor proved to be significantly dependent (P < 0.05) on the amount of added extract.