Guiding Principles for Hygienic Design of Evaporators to Mitigate Contamination-Related Risks in Air Blast Freezing Systems

Evaporator coils, fins and drain pans in blast freezers may act as a source of microbial, physical and chemical contamination (representing Critical Control Points within a HACCP study). For instance, the evaporator might contaminate unpacked food products passing through the freezer with undesirable ingredients remaining from a previous product being frozen. Drain pans below the refrigerating coils and fans also require paramount attention, due diligence and professional care to ensure that both frozen foods and freezer interior are kept at the highest possible hygienic level. This book chapter is, therefore, focussing on knowledge-based hygienic design of evaporators in air blast freezing systems (e.g., proper production and mounting of refrigerating coils, drain pans and fans, along with suitable materials of construction to reduce frosting, microbial fouling and corrosion) with the ultimate aim of acquiring a safe environment and extended shelf life of unwrapped products. An overview of the existing types of air blast freezers is presented for that purpose. Furthermore, the today’s state of the art is introduced to food chain operators who are not enough familiar with hygienic design. Typical contamination problems and measures for contamination control are discussed as well. Guiding Principles for Hygienic Design of Evaporators to Mitigate ContaminationRelated Risks in Air Blast Freezing Systems