Fluidised bed drying
The differently pre-treated cut samples were dried in a pilot plant fluidised bed dryer (ATP, Berlin, Germany, Model MS 1016) at 60°C for 6 h and the velocity of air was 1 m/s. During the dehydration of paprika subjected to different pre-treatments (such as blanching, skin pre-treatments, and physical pre-treatments, e.g. HHP and HELP), the moisture contents (X) at different drying times were experimentally determined. The weight loss of samples was recorded at 30-min intervals. The wet bulb and dry bulb temperatures were 30 and 63°C, respectively. The drying equipment was of a closed loop type with hot air re-circulation, having a power driven fan blowing air through a heating section from where the heated air branched into an air velocity controlling valve and air bypass valve, and then through the drying chamber consisting of a metal container with a mesh base which allowed a through-flow of the heated air.