Predictive Microbiology for Monitoring Spoilage of Dairy Products with Time‐Temperature Integrators

Time/temperature integrators (TTI) have a potential for monitoring time‐temperature history of perishable foods, including dairy products. To correlate the end of shelf life of dairy products with different TTI's, kinetic data for growth of a dairy spoilage microorganism was obtained. Both Arrhenius and square root equations were used to model the growth of Pseudomonas fragi. A significant negative history effect was observed for P. fragi growth rate whereas history effect was positive on the lag phase, under certain nonisothermal conditions. A correlation scheme of P. fragi growth was developed with the TTI response. The application of TTI's for dairy products is feasible despite the history effects. Copyright © 1991, Wiley Blackwell. All rights reserve

Cold chain database development and application as a tool for the cold chain management and food quality evaluation

International audienceCold chain management can optimize freshness and safety to the consumer end. Within FRISBEE European project (http://frisbee-project.eu) a web-based platform was developed for temperature conditions data collection throughout the chilled and frozen food supply chain. Data including all cold chain stages (industry, distributors, retailers and consumers), were collected. This extensive database comprising more than 14,000 time-Temperature (t-T) profiles can serve as a valuable Cold Chain Management tool. The user can define a sequence of cold chain stages for selected food products. The Cold Chain Predictor (CCP) software based on the Cold Chain Database (CCD) allows calculation of product shelf-life status at different cold chain stages based on existing or user defined kinetic data. Conducted field tests expanded the Cold Chain Database and validated the software. The developed tools offer the potential to run simulation scenarios based on real cold chain data and contribute to effective cold chain improvement and management

Monitoring the effect of high pressure and transglutaminase treatment of milk on the evolution of flavour compounds during lactic acid fermentation using PTR-ToF-MS

In this study, the effects of thermal or high hydrostatic pressure (HHP) treatment of a milk base in the absence or presence of a transglutaminase (TGase) protein cross-linking step on the flavour development of yoghurt were investigated. The presence of several tentatively identified volatile flavour compounds (VOCs), both during the enzymatic treatment and the lactic acid fermentation of the milk base, were monitored using a proton transfer reaction time-of-flight mass spectrometer (PTR-ToF-MS). The formation of the major flavour compounds (acetaldehyde, diacetyl, acetoin, and 2-butanone) followed a sigmoidal trend described by the modified Gompertz model. The HHP treatment of milk increased significantly the volatile compound formation rate whereas it did not affect the duration of the lag phase of formation, with the exception of acetaldehyde and diacetyl formation. On the contrary, the TGase cross-linking of milk did not significantly modify the formation rate of the volatile compounds but shortened the duration of the lag phase of their formatio