For food processing, it is important that the plant design takes into account factors affecting the hygienic operation and cleanability of the plant. (See also previous guidelines on hygienic design criteria Doc 8, hygienic welding Doc 9, and the hygienic design of equipment for closed processing Doc 10.)
The risk of contamination of food products with relevant micro-organisms during open processing increases with the opportunity to grow in poorly designed equipment, as well as with the concentration of the micro-organisms in the environment. This means that in open plants, environmental conditions, in addition to appropriate equipment design, have an important influence on hygienic operation. Furthermore, the type of product and the stage of the manufacturing process must be taken into consideration. Open processes incorporate many different types of equipment, including machines for the preparation of dairy products, alcoholic and non-alcoholic drinks, sweet oils, coffee products, cereals, vegetables, fruit, bakery products, meat and fish.
This paper deals with the principal hygienic requirements for equipment for open processing. It describes methods of construction and fabrication, giving examples as to how the principal criteria can be met in open process equipment.