Recent Developments in Drying Technologies for Foods

Abstract

Thermal dehydration is the most common and cost-effective technique for the preservation of foods and for the production of traditional as well as innovative processed products such as snacks with desired functionalities. This chapter provides an overview of recent developments in thermal drying technologies that are already commercialized or show potential of industrial exploitation upon successful R&D to sort out some limitations. New dehydration technologies are needed to enhance quality, reduce energy consumption, improve safety, and reduce environmental impact. Mathematical modeling can be used for the cost-effective development of novel designs to reduce the cost and time required for innovation. As examples of some emerging drying techniques this chapter provides relevant details on heat-pump-assisted drying, superheated steam drying, pulse combustion spray drying, variable pressure drop drying (swell drying), and novel gas-particle contactors such as impinging streams and pulsed fluidized beds. Multistage drying, intermittent drying, and the use of hybrid drying technologies that combine the advantages of different dryer types without some of their limitations will be outlined.