Fighting food pathogens
cent of outbreaks today associated with meat, fresh fruit,
vegetables and salad.
Despite improved measures in the area of food hygiene and food control, pathogens are still increasing throughout Europe with over 60 per cent of outbreaks today associated with meat, fresh fruit, vegetables and salad. A new European funded project is set to get to grips with the contaminating pathogens.
Led by Judith Evans at Bristol university's Food Refrigeration and Process Engineering Research Centre, the overall objective of the project, aptly named Bugdeath, is to improve food safety by better control in thermal processing, in particular using High Temperature Short Time (HTST) processing, heating and cooling cycles, but also in slow thermal processing.
Food pathogens are mostly located on the surface of foods and so controlling surface pasteurisation makes for a crucial issue.
According to the project organisers, the objective will be achieved by establishing more accurate models of microbial death in response to the processing.
After one year of study the scientists involved in the project report that they have constructed 'accurate and very flexible apparatus which may heat or cool the food between 5 and 120°C in both wet and dry environments.' The temperature cycles are repeatable within more or less 2°C and the accuracy of measuring food surface temperatures is better than 1°C.
In addition, they have introduced a "lux-gene" into the test pathogens allowing these to glow (bioluminescence) only when alive. This enables the scientists to quickly measure the effect of thermal cycles as the bioluminescence fades when the treatment is effective.
The researchers have also created heat transfer and microbial death models. They report that these models will be verified against data obtained from the apparatus developed within the project and combined to create a model to predict the effect of temperature changes on the food surfaces to microbial death.
