Rural Industries Research & Development Corporation

Research Compendium 1993 - 1994

Research Project

APPLICATION OF PREDICTIVE FOOD MICROBIOLOGY TO IMPROVE THE QUALITY AND SAFETY OF FOOD

Objectives

• To derive and validate in industry mathematical models to predict the effects of environmental factors on the rates of growth of spoilage and pathogenic microorganisms; to enable prediction of the shelf life and microbiological safety of food products.
• To make the results available to industry by developing computer software to interpret the effects of processing and storage conditions on bacterial proliferation.

Background

The assurance of microbiological quality and safety is a prerequisite for maintaining existing markets for food products and developing new ones. Hygienic processing operations can minimise the level of contamination by pathogenic bacteria but cannot be relied upon for total elimination.

The opportunity exists to prevent these problems by developing systems to monitor and predict the extent of microbial growth. Knowledge of the growth responses of microorganisms to environmental conditions enables objective evaluation of the effect of processing, distribution and storage operations on the microbiological safety and quality of foods.

This area of research has come to be known as 'predictive microbiology', and has received considerable international interest, both in industry and research organisations, some of which have undertaken major collaborative projects as a result of major food poisoning incidents.

Research

Growth rates of microorganisms, isolated from a variety of foods, were determined in artificial broth media under many conditions of temperature and water activity. Mathematical models, based on thousands of data for a number of bacterial species, including psychrontrophic pseudomonads and Listeria monocytogenes, were developed. Predictions from these models were validated in the laboratory in food products before being incorporated into computer software.

Outcome

Professionally written software embodying the results is currently undergoing industry evaluation to assess its accuracy, ease of use and reliability to predict the proliferation of bacteria in foods. Feedback from industry will be used to prepare final versions for general release.

Implications

Use of predictive food microbiology will benefit the food industry by:

• minimising the risks of food-borne disease outbreaks;
• allowing better estimates of product shelf life, which allows development of more distant markets;
• enabling rational development of microbiologically 'safe' food products and processes; and
• objectively, quantitatively, assessing deficiencies in processing and distribution systems.

RIRDC Project No: UT-4A

RESEARCHER: Professor Tom McMeekin

ORGANISATION: University of Tasmania

PHONE: 002 202 637

PUBLICATIONS:

McMeekin, T A, Olley, J N, Ross, T and Ratkowsky, D A, 1993, Predictive Microbiology: Theory and Application. Research Studies Press Ltd. England, 340pp.

Ross, T and McMeekin, T A, 1994, Predictive Microbiology. IntJ.Food Micro. 23, p241.

Ross, T and McMeekin, T A, 1993, Predictive Microbiology and HACCP. In Hazard Analysis Critical Control Point (HACCP) in Meat Poultry and Seafoods. (A Pearson and T R Dutson eds), Blackie Academic and Professional.

Last updated: 10 October 1996
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