ABSTRACT
This chapter discusses a brief review for impingement studies in food processing and considers the analysis of heat transfer and fluid flow phenomena during an impingement process. A promising development in the food processing area to reduce the processing time in freezing, thawing, baking and drying of foods is impingement heat transfer. In traditional heating/cooling methods using air or slowly agitated air, a thermal boundary layer develops around the product which slows the heat transfer rate. Determination of heat transfer coefficient has been generally the first step in analyzing impingement thermal processing. Higher heat transfer coefficient and its spatial variation have been noted in each study of impingement thermal processing. Combined air impingement with, such as, microwave processing were reported to be a practical solution to improve the heating uniformity and to better control the moisture transport within the product in aiding the surface crust formation.
