Chapter 11: Controlling the Microbiological Quality of Foods

Understanding how micro-organisms behave in food facilitates their control and the maintenance of a food’s quality, safety and reliability is key. Microbiological examination of product samples can help confirm quality and microbiological criteria for foods are published. Reliance on microbiological testing alone is, however, unsuitable for controlling quality since it is retrospective and the incidence and distribution of micro-organisms in foods limit how representative results from a restricted number of samples can be an indication of quality in a whole batch. More effective, is to control quality at source during processing. Good manufacturing practices need to be employed to ensure staff are sufficiently trained, facilities and equipment are hygienically designed and that operations of manufacture and cleaning are sufficient and properly conducted. This is often enshrined in Codes of Good Manufacturing Practice, although these are of general applicability and may lack specificity. The Hazard Analysis Critical Control Point (HACCP) concept – a systematic, rule-based approach to preventative quality control, tailored to a particular enterprise – is described. A systematic, scientific approach to microbiological risk assessment has been used by regulatory authorities, including the World Health Organization, to provide objective estimates of the probability of occurrence and severity of particular foodborne hazards. It forms part of the overall Risk Analysis system by which governments can set public health goals. Designated an ‘appropriate level of protection’ these can, in principle, be translated into concrete objectives for the food industry, such as a Food Safety Objective, Performance Objectives or Performance Criteria, which procedures such as HACCP can help deliver.