INTERMITTENT DRYING OF NOPAL (OPUNTIA FICUS INDICA) IN A FLUIDIZED BED PILOT DRYER ADAPTED WITH REVOLVING CHAMBERS

摘要

Intermittent drying is a novel method for improving the food drying kinetics,rnenhancing product quality and reducing energy consumption per unit of moisturernremoved at the lab scale. However, the drying protocol itself makes it difficult tornimplement it at the pilot plant scale without important energy loses. Taking thisrninto account, an accessory for a fluidized bed pilot dryer was developed using anrnarrangement of revolving chambers that could increase the efficiency of the dryingrnprocess; nopal (Opuntia ficus indica) was employed as a food material. Severalrndrying experiments were conducted at the laboratory scale in order to establishrnthe most appropriate drying condition to be further tested at the pilot plant scale.rnNo statistical difference was observed between the drying curves obtained inrnthe laboratory and pilot plant dryers under conventional and intermittent dryingrnconditions, which means that the arrangement of chambers guarantees equal andrnconsistent treatment of the solid. Interestingly, the results indicate that a dryingrnprotocol of nopal size “E” using the adapted fluidized bed dryer with temperingrncycles at pilot plant scale can be regarded as an excellent and cost-effective methodologyrnfor processing vegetables without chemical quality losses.