Wrapping to play part in greater safety

FOOD in the modern supermarkets is more enticing than ever. Colourful packaging, improved presentation and greater use of preservation techniques easily cast a spell.

That, nonetheless, does not translate into greater risks to the consumer, as many suspect. "It would be a very foolish processor who would put presentation, for instance, ahead of safety," says food microbiologist Dr Mary Upton of UCD.

Packaging, if anything, has improved through "better design, better materials". All this, however, has to be couched in a key fact of microbial life: many novel methods of food processing have come on stream but a slight alteration in method of packaging, preparation or storage can influence the risks - and present the opportunity for a pathogen to exploit a microbial window of opportunity.

Novel approaches need to be monitored very carefully. Take the sous vide process so beloved of the French. It essentially involves vacuum packaging with a mild heat process and is used with meats and ready to eat dishes. Not surprisingly, the French like the notion of preparing a gourmet dish, and all you have to do is reheat it.

Essentially, the food is vacpacked, pasteurised, stored at low temperature, reheated and served. "In theory, it should be okay. In reality, it needs very careful monitoring with competent technical people," she says.

Modified atmosphere packaging (MAP) is also popular with meat and vegetables. The air around a food item is exchanged with, for example, a higher concentration of carbon dioxide. It extends shelflife by removing spoiling microbes when used with low temperature storage. But eliminating one kind of bacteria may enable other pathogens, bacteria that live without oxygen, to jump in and thrive. They are more than able to survive the new regime. Again, it's back to proper control and management.

Packaging generally is not a source of great worry, Dr Upton says. There are more obvious critical points in the food chain. The role of butchers who sell both raw and cooked meat is one. Equally, food scares have led to the realisation that "things grow quite cheerfully" at low temperatures.

Refrigerated trucks, therefore, assume vital importance as temperature abuses can create entirely new environments for bugs to exploit. All associated risks, however, can be dramatically reduced, if not eliminated, by information, education and training.

The future for packaging will, no doubt, incorporate greater food safety. An instant test for the dreaded E coli, developed by scientists at California's Berkeley National Laboratory, is likely to be part of food wrappers within a year. In Britain, Sainsburys and Marks & Spencer have announced they are to sell products impregnated with microban, a disinfectant that can kill a wide range of bacteria including foodpoisoning pathogens. It will be incorporated into chopping boards, dishcloths, binliners and towels.