Optimization of foam mat drying for instant coffee processing and its effect on drying kinetics and quality characteristics
Kátia Silva Maciel, Luciano José Quintão Teixeira, Suzana Maria Della Lúcia, Sérgio Henriques Saraiva
Abstract
The influence of different contents of maltodextrin and whey protein isolate was investigated in the coffee foam, drying kinetics, sensory acceptance of cappuccinos (added of instant coffee) and solubility, antioxidant capacity, wettability, and moisture content of dried samples. The desirability function was used to define the optimum process condition. Shorter drying times and greater stability were achieved using higher concentrations of whey proteins than maltodextrin for foams. The results analyzed showed significantly higher retention of bioactive components, low moisture and high wettability of powders. The Midilli model was the most appropriate to represent the drying kinetics. The foaming agents contributed to improving the quality characteristics (aroma, taste, and overall impression) of instant coffee (p < 0.05). There was no influence of the foaming agents on the solubility and density of the powders (p > 0.05). The combination of the agents of 1.32% of maltodextrin and 2.64% of whey protein isolate obtained greater overall desirability (0.6503).