Air-suspension particle coating in the food industry: Part I — state of the art

Air-suspension particle coating has been slow to develop in the food industry. This is not surprising considering the economic constraints for low cost ingredients and low cost processing. Therefore, a need exists to adapt the process and formulation knowledge developed in the high-value pharmaceutical and health care industries to higher volume, low-cost production in the food industry. This paper reviews the current state of the art of air suspension coating as applied to the food industry. Of the few current applications, most have been developed by statistical experimentation which belies an understanding at the interface between food science and process engineering. This review concludes that a phenomenological approach is necessary in order to advance knowledge and accelerate product development. Such an approach will yield results independent of both the substrate powder and the coating device, which can be applied widely to select suitable coating materials and methods of application. A following paper will then elucidate key micro-level phenomena and discuss their implications.