Food Protection Trends - November 2008 - 797

of food tested (3). These confidence limits assume random distribution of the organisms within the food and that there is no variance related to analytical methods or analysis. In reality, microorganisms are not always randomly distributed and there is always some variance related to methods, laboratories and analysts. The total variance related to analytical result is defined as uncertainty (4). Applications of microbiological testing Despite the limitations and uncertainty of sampling and testing for microorganisms, microbiological testing is almost always an important component of any program to assure the safety and quality of foods at all levels of government and industry. Microbiological testing is performed to establish background information, verify control, or to reach a decision or judgment. Examples of decisions or judgments related to microbiological testing include: verification of the safety of a product, assessing adherence to good manufacturing/hygiene practices (GMP/GHP), determining the utility of a food or ingredient for a particular purpose, predicting shelf life of a product, and verification of compliance to established microbiological criteria; e.g., regulations, purchase specifications, internal guidelines, etc. Microbiological testing plays an essential role in HACCP plans and pre-requisite programs. Data may be utilized to validate processes and to verify control. Products that are to be used by at-risk groups or which contain no lethal step may require microbiological testing to monitor the safety of ingredients and/or finished products. Testing can be used to verify the efficacy of cleaning and sanitizing procedures and determine the presence of pathogens in the processing environment. Understanding the prevalence and distribution of microorganisms in the processing environment is essential to prevent contamination of products that do not receive a lethal process in their end-use packaging. This is exemplified by the number of products recalled in recent years that included a validated lethal process prior to packing. Considering the number of outbreaks and recalls associated with plants operating with HACCP plans, it is prudent to consider ongoing microbiological testing as verification that the plan is effective and the process is under control. Microbiological testing of ingredients and finished products to demonstrate compliance with microbiological criteria, such as regulatory standards, internal company specifications and purchase specifications, constitutes a large percentage of microbiological tests conducted by industry. Moreover, concerns about the potential for litigation encourages companies to develop test data as documentation of due diligence, even when they have a high level of confidence in their processes and systems to deliver safe and high quality product. Although it has been many years since the International Commission on Microbiological Specifications for Foods (ICMSF) provided guidance on development of microbiological criteria, many microbial limits set by industry and government fail to include necessary components that determine the reliability of the data for the purpose intended. Even when these components have been defined, they are often set without a clear understanding of the uncertainty associated with the distribution and state of the target organism(s) in the food, and the methods of sampling and testing. For example: • Application of sampling statistics based on random distribution to when the distribution is non-random or unknown Insufficient number of samples to draw valid conclusions about the acceptability of a product, such that, negative results have little value, and data is only meaningful if the tests indicate non-compliance Re-testing of product that failed initial testing and accepting a desirable re-test result without considering that such results might be related to distribution rather than a laboratory error on the first test Establish of zero-tolerance criteria, even though no practical sampling plan and testing protocol can assure the absence of a pathogen Often microbiological data exist that is only examined relative to pass/fail criteria on a given unit of production or moment in time for environmental tests. Trend analysis of this data may identify potential problems or can add confidence that the process is under control • • • • the future Despite the limitations and inappropriate applications of microbiological testing today, there is hope for the future. Risk-based Food Safety Objectives (FSO) which translate public health risks into definable goals; i.e., “the maximum frequency and/or concentration of a hazard in a food at the time of consumption, that provides or contributes to the appropriate level of protection (ICMSF, 2002). This approach enables the food industry to meet a specific goal by application of GMP/GHP, validated HACCP systems, performance criteria, process/product criteria, and acceptance criteria. FSOs provide industry with a scientific basis to select and implement control measures from farm-to-fork. Performance Objectives (PO) may NOVEMBER 2008 | FOOD PROTECTION TRENDS 797
Food Protection Trends - November 2008

Table of Contents for the Digital Edition of Food Protection Trends - November 2008
