For reasons too dull to go into I haven’t been able to add new posts as often as I would like recently. But I consoled myself with the thought that not much happens in August anyway. So I was somewhat taken aback to discover that a quick scan of the food safety news for the last few weeks revealed a flurry of serious food poisoning outbreaks, especially in the USA. The foods involved feature several of the usual suspects, including cheese and ground beef, but two major US Salmonella outbreaks have been linked to mangoes and cantaloupes.
Outbreaks associated with fruit and vegetables seem to be occurring more and more often in America, with cantaloupes involved in several, notably last year’s nationwide listeriosis outbreak, which killed 33 people. That being the case, I was interested to read about a study conducted at the Institute of Food Research (IFR) in England investigating a technology called cold atmospheric gas plasma (CAP) as a method of decontaminating fresh produce. CAP uses highly energised and ionised gases at room temperature to destroy bacteria on surfaces without affecting food quality and has proven quite effective at a laboratory scale. Unfortunately, the IFR researchers found that the lumps, bumps and holes that cover the surface of many fruits and vegetables protect bacterial cells from the effects of CAP to varying degrees. Electron micrographs show surfaces that are far from smooth, with plenty of nooks and crannies where bacteria can hide. Nevertheless, the researchers conclude that the technique has promise.
Several different technologies have been proposed to decontaminate fresh produce – ozone and ultraviolet light treatment being just two examples – but chlorinated water remains the only treatment in common use. Unfortunately, this too is rather hit and miss in its effectiveness, and can be difficult to apply consistently. Despite years of research, no practical alternative has yet been found. Perhaps efforts would be better concentrated on improvements to good agricultural practice and on applying better HACCP-style controls at the early stages of harvesting and packing. Decontamination only has a purpose when the product is already contaminated. Finding ways to prevent that contamination could be more effective and might even save lives.