Beef is a commercially important and widely consumed muscle food and central to the protein intake of many societies. In the food industry no technology exists for the rapid and accurate detection of microbiologically spoiled or contaminated beef. Fourier transform infrared (FT-IR) spectroscopy is a rapid, reagentless and non-destructive analytical technique whose continued development is resulting in manifold applications across a wide range of biosciences. FT-IR was exploited to measure biochemical changes within the fresh beef substrate, enhancing and accelerating the detection of microbial spoilage. Separately packaged fresh beef rump steaks were purchased from a national retailer, comminuted for 15 s and left to spoil at ambient room temperature for 24 h. Every hour, FT-IR measurements were collected directly from the sample surface using attenuated total reflectance, in parallel the total viable counts of bacteria were obtained by classical microbiological plating methods. Quantitative interpretation of FT-IR spectra was undertaken using partial least squares regression and allowed for accurate estimates of bacterial loads to be calculated directly from the meat surface in 60 s. Machine learning methods in the form of genetic algorithms and genetic programming were used to elucidate the wavenumbers of interest related to the spoilage process. The results obtained demonstrated that using FT-IR and machine learning it was possible to detect bacterial spoilage rapidly in beef and that the most significant functional groups selected could be directly correlated to the spoilage process which arose from proteolysis, resulting in changes in the levels of amides and amines.

Risk-analysis of human pathogen spread in the vegetable industry: a comparison between organic and conventional production chains E. Franz # , A.H.C. van Bruggen # and A.M. Semenov ## An overview is given of recent problems with food-borne enteric human pathogens originating from contaminated agricultural animals. The need for risk analysis is indicated, and the generally accepted procedure for risk assessment is outlined. Two main approaches to probability and risk calculations, namely the “frequentist ” and Bayesian approaches, are described. Examples are given of microbial risk assessments in vegetable production that were mainly based on “frequentist ” probability assessments. Finally, a Dutch-Russian collaborative project on risk assessment of enteric pathogens in organic and conventional vegetable production chains is outlined, and preliminary data are presented. We conclude that a Bayesian approach, using prior probabilities, is the most appropriate instrument for risk assessment of human-pathogen spread in the vegetable industry.

Although numerous papers on Microbiological Risk Assessment (MRA) of food products have been published, a number of issues related to it remain unresolved. This paper explains the role of Microbiological Risk Assessment in the context of Risk Analysis as outlined by Codex Alimentarius. It reviews some representative work in the area, with particular emphasis on the objectives, outputs and conclusions of the studies, and on how researchers propose using the resulting Risk Estimate for decision making. Several problems and sources of confusion concerning MRA are identified, such as terminology, the application of Risk Estimates to establish Food Safety Objectives and microbiological criteria for foods, lack of data, and the difference between Risk Assessment and the Hazard Analysis and Critical Control Point system (HACCP). In the context of Codex Alimentarius, MRA was developed as a tool for decision making and priority setting by government risk managers. However, elements of Risk Assessment can be used for other purposes. A transparent description of a Risk Assessment study is useful for Risk Communication. Industrial food safety managers can compare the effect of various hypothetical production scenarios using estimates of the level and the probability of a pathogen in the product at the time that it is consumed. This limited form of Risk Assessment could better be called Safety Assessment, and can be used as a tool for food product and process development. Key words: Risk assessment, food microbiology, microbial ecology, Codex Alimentarius

This guideline document represents the current thinking of the workgroup on the topics addressed. It is not a regulation and does not confer any rights for or on any person and does not operate to bind USDA, EPA, any other federal agency, or the public. Further, this guideline is not intended to replace existing guidelines that are in use by agencies. The decision to apply methods and approaches in this guideline, either totally or in part, is left to the discretion of the individual department or agency. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.