USE-BY dates are the best guide we have for telling whether food is still safe to eat, but they aren鈥檛 particularly accurate. A sticker that senses harmful bacteria may soon provide a more precise way to check if what鈥檚 in your fridge is fit for the plate, reducing waste.
London-based start-up Fresh Check has already been testing its spray version of the new safety system in abattoirs, restaurant kitchens and sandwich-filling facilities since April, where it can detect contamination on food handling surfaces. The product has now been given the OK by Campden BRI, an independent food safety authority, and Fresh Check made its first sale earlier this month, to a ready-meal firm.
Such safety checks are usually done with swabs, plastic sticks containing an enzyme that reacts with adenosine triphosphate, a molecule made by all living cells including bacteria. But this method is expensive and fiddly, says John Simpson at Fresh Check.
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Instead of a biological reaction, Fresh Check鈥檚 spray uses a chemical reaction that flags the presence of a protein produced by bacteria but not mammalian cells. It is cheaper and longer lasting than a swab test, meaning it can be kept close to hand and used for frequent spot checks. Spray it on a surface and the liquid changes colour if bacteria are present.
Bacteria that can cause illness, such as listeria and some strains of E. coli, are quite prevalent, says Simpson, who is 鈥渉oping for a bump in hygiene standards鈥�.
Food safety professional Lisa Ackerley was an early fan and has been advising the company. She thinks the spray will be especially useful for testing surfaces used for preparing food that is ready to eat, such as a food slicer in a deli or a countertop where sushi is made. 鈥淵ou can鈥檛 judge a surface by visible cleanliness,鈥� she says.
Ackerley has also carried out hygiene checks in hotels and sees a use for the spray there, to let managers see if rooms have been properly cleaned. 鈥淚鈥檝e quite often found the cups or glasses are dirtier than the toilet,鈥� she says.
Fresh Check is now planning to develop hand wipes that use the chemical test. It also wants to make stickers containing the spray that can be put inside food packaging. These would change colour when meat or fish were no longer safe to eat, giving a more precise way to monitor freshness than a use-by date.
People in the UK throw away around 41 per cent 鈥� or 2 million tonnes 鈥� of the food they buy each year because they think it is no longer safe to eat, according to estimates by the charity Waste and Resources Action Programme (WRAP). A third of that food was binned because of advice such as use-by dates on packaging, says Andrew Parry at WRAP. However, such food may often still be safe.
Fresh Check is talking to supermarkets about placing their stickers in packaging. But costs are still too high for the big chains to bite. Each food package costs them a fraction of a penny to make and anything that increases that even by a tiny amount cuts into their margins, says Simpson.
This article appeared in print under the headline 鈥淪pritz to check for food safety鈥�
