Hot Tips on Bad Bugs for Better Food

08 September 2003

Discovering why some foods spoil and how bacteria survive heat treatments designed to preserve our produce has got one step closer, according to Dutch scientists presenting their research today, Monday 8 September 2003, at the Society for General Microbiology's meeting at UMIST in Manchester.

Being able to identify contaminants accurately, and early on, could allow us to buy crunchier vegetables and less highly processed food in the future according to the researchers.

In a food science initiative supported by the Dutch government, scientists from the University of Amsterdam looked at the way the Bacillus group of bacteria can produce exceptionally heat resistant spores. These spores can survive the processes meant to kill them, like pasteurisation, and go on to grow, multiply and contaminate our food.

"We are using molecular techniques to uncover the heat resistance secrets of these spores, and to find out how they survive the preservation processes," says Dr Bart Keijser from the University of Amsterdam. "Once we have identified their unique genetic fingerprint, we can design new detection systems to find any micro-organisms that have survived heat treatment. This will give the food industry the chance to adjust their food production and preservation processes."

Until now the food industry has had to assume that in every case, the worst possible type of contamination has already happened, leading to over-processing of most foods. Using the scientists' results, companies will be able to pre-screen ingredients, use the best preservation method in each case, and reduce energy costs and losses from contamination while maintaining safety levels.

"I hope this will mean we need less preservation techniques, and so less processing for most food. That should give us enhanced food structure such as crispier vegetables, while still maintaining a long shelf time," says Dr Bart Keijser.

The research work has already identified more heat resistance from the bacteria when some food ingredients such as milk powder and spices are used. The amount of minerals the spores can absorb also seems to contribute to their heat resistance.

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