ABSTRACT
Drying is a most commonly used unit operation. Drying technique is traditional food preservation technique known to mankind. The material to be dried that form a bed can be fluidized if the pressure drop through the bed is equal to the weight of the bed, reaching the expansion and suspension in air of the particle. The spray drying is being used to dry liquid foods to a dried particulate form by spraying the feed onto a hot drying medium. Innovative technology like microwave vacuum drying and Superheated steam drying improved quality of fruits and vegetables but does not resolve issues of texture control, microbial decontamination and powder production. Effect of supercritical carbon dioxide was studied on carrots by Brown and co-authors and comparison was carried out with hot air drying. It was reported that supercritical carbon dioxide dried carrots displayed better textural characteristics, retained shape and less shrinkage than hot air dried samples.
