ABSTRACT
Conventional air-drying techniques such as spray drying, for example, require low-temperature operation, which prolongs the drying time and may even lead to undesirable microbiological reactions. Vacuum drying and microwave (MW)-vacuum drying reduce the temperature of evaporation, but the loss of volatile fl avor species can still be signifi cant. Freezedrying, however, allows product quality to be maintained, but the process is diffi cult to carry out at a rate fast enough to be economically justifi ed for most fruit juices.
