Use of Time Temperature Integrators in food safety management

Distribution, retail and domestic storage of food are considered as the weaker links in a food safety management system. Conditions during the above stages of the food chain are out of manufacturer's direct control and often deviate from specifications. This lack of control may result to increased microbial growth and negate the efforts made in improving and maintaining food safety at the earlier stages of the chain via Hazard Analysis and Critical Control Points system, Good Manufacturing and Hygiene Practices. Ideally, a cost-effective way to individually monitor the temperature conditions of food products throughout distribution, retail and domestic storage, indicating their real time–temperature history, would be an effective safety management tool. Time Temperature Integrators (TTIs) could potentially fulfill the above requirements. Despite the extensive research on the application of TTIs for monitoring food spoilage and quality, however, limited information is available for their use in food safety management. The objective of the present study is to present the state of the art and application scheme of TTIs in food safety management. The effectiveness of TTIs in improving food safety is demonstrated through a case study for Listeria monocytogenes in Ready-to-Eat foods. We show that a microbial TTI can assure a maximum limit in the growth of the pathogen from production to consumption time by informing the consumers when this limit is exceeded in a product unit. The latter limit, which we call Growth Tolerance Criterion, can be considered as a Performance Criterion for the growth of L. monocytogenes during distribution and storage. The applicability of the microbial TTI in reducing consumer exposure to L. monocytogenes is also presented using a probabilistic approach.