Degradation of Vitamin C in Spray Dryers and Temperature and Moisture Content Profiles in these Dryers

The occurrence of peak solid temperatures inside cocurrent dryers, including spray dryers, is relevant to their use for producing food powders. A numerical simulation has been used here to explore the location of the maximum degradation rates in a small-scale Buchi cocurrent spray dryer used to dry vitamin C, finding that the maximum degradation rates are likely to coincide with the peak particle temperatures. The peak particle temperatures are likely to occur shortly after the inlet of the dryer and before the outlet, irrespective of the amount of heat loss from the dryer.