Recent developments in the spray drying of sugar-rich products such as fruit juices, pulp and honey with and without the application of carriers, e.g., carbohydrate carriers (maltodextrin, gum arabic), prebiotic dietary fibers, proteins and natural carriers have been presented in this paper. The effect of the carrier type, carrier concentration and the spray drying process parameters on the product yield and selected final product properties are analyzed and discussed. Recent studies have proved that prebiotic dietary fibers and proteins may substitute conventional carriers, i.e., refined carbohydrates, providing high product yield and additional nutritional value at lower carrier concentration in the final product.

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Drying is an extremely energy-intensive process. Superheated steam as a drying medium can improve the energy efficiency of the drying processes. In superheated steam drying, waste heat can be recovered by condensing the exhaust steam or raising its specific enthalpy. Spray drying is widely used in industry, even though its energy efficiency is often low. Substitution of air by superheated steam as a drying medium in a spray dryer may reduce the energy consumption of the drying process by 20–30%; moreover, if excess steam generated by moisture evaporation is upgraded to a higher temperature level and reused for drying, the energy demand could be decreased by even 80%. A literature review showed that superheated steam spray drying was successfully applied for both thermally resistant and a wide range of thermally sensitive materials. Superheated steam drying gives a number of advantages in terms of product properties, i.e., higher particle porosity due to rapid moisture evaporation results in improved powder rehydration properties. Additionally, steam drying may be applied for in situ particle crystallization. Taking into account the advantages of superheated steam drying and the potential application of this technology in spray drying systems, there is a great need for further research in this field. This literature review aimed to present an energy-saving solution, i.e., superheated steam spray drying process, showing its advantages and potential applications, followed by drying kinetics, providing analysis of the research papers on experimental studies as well as mathematical modeling of this drying technique.

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