Spray-freezedrying: A novel process for the drying of foods and bioproducts

Spray-freeze-drying (SFD) is an unconventional freeze drying
technique that produces uniquely powdered products whilst
still including the benefits of conventionally freeze dried products.
SFD has potential applications in high value products due
to its edge over other drying techniques in terms of product
structure, quality, and the retention of volatiles and bioactive
compounds. In cases where other drying techniques cannot
provide these product attributes, SFD stands out despite the
costs and complexities involved. This paper outlines the principles,
methods, significant process parameters, particle
morphology and quality aspects of SFD. Recent developments
in this technique are reviewed including ultrasonic sprayfreeze-
drying, the application of computational fluid dynamics
and mathematical modelling, and the incorporation of new
technologies to improve product quality. In addition, the advantages,
limitations and future scope for research in the field
of SFD are discussed.