Enhancing properties of coffee instant powder by microencapsulation using the freeze-drying method: comparison between wet- and dry-blending

Instant coffee production is generally obtained through a drying process by freeze-drying, which utilizes low temperatures, making it suitable for preserving volatile compounds. This study aimed to determine the effect of freeze-dryer conditions and the impact of wet and dry blending methods on the properties of instant coffee. The experimental variations in this study include drying time (48 and 72 h), coffee extract concentration (0.5 g/mL and 0.25 g/mL), and maltodextrin ratio (without maltodextrin, 1:10, and 1:15). The best variations of instant coffee in terms of moisture content, solubility, hygroscopicity index, light index (L), and CGA levels were the coffee powder with drying time of 48 h and extract concentration of 0.25 g/mL, with values ranging from 2.8-4.1%, 92-93%, 7-16%, 25-31, and 855-1408 ppm, respectively. Wet blending method (1:10 maltodextrin) was found to give the highest preference level, with an average preference level of 5.06 from 6.