Effect of superheated steam drying on properties of foodstuffs and kinetic modeling

Abstract

Abstract Conventional hot air drying is an energy intensive technique which consumes around 15–25% of national industrial energy in most of the countries. It also often results in unacceptable product quality, nutrient degradation and non-uniform drying. Using air as a drying media leads to oxidation and combustion reaction and releases undesirable components creating environmental issues. Drying operation also needs continuous improvements to reduce energy consumption and preserve quality. Superheated steam drying (SSD) is an innovative drying technology, utilizing heated steam beyond its boiling point as a drying medium in a dryer to remove excess water from the material. Researchers on comparing conventional and SSD claimed that SSD supports product, environment, and energy saving benefits as well as it overcomes many constraints of hot air and other conventional drying techniques. This review will provide comprehensive detail about the effect of SSD on different properties (texture, microstructure, color, nutrient retention, shrinkage) of foodstuffs. Mathematical modeling and simulation of the SSD process as well as product characteristics undertaken by researchers are also compiled briefly in this article. Industrial relevance SSD offers many advantages over hot air drying which includes low net energy consumption, utilization of exhaust steam, no oxidative reactions and no hazardous gas, dust, dirt emission into environment. Kinetic modeling may prove to be useful for optimization and designing of the process.