A confusing dial on some fridges controls power, and if set too low, the appliance may not be cold enough, according to Dr Xand van Tulleken. Fridges are designed to slow down bacterial multiplication by keeping food cool. At room temperature, bacteria can double every 20 minutes, leading to millions or billions by the end of a day, Dr van Tulleken explained.
He noted that in the UK, there are about two million instances of food poisoning annually, leading to dozens of preventable deaths and significant lost work and suffering. The main culprits are salmonella, E. coli, and listeria, Dr van Tulleken said.
A fridge thermometer can help ensure the temperature is at 4°C or less, which is the target for safe food storage, Dr van Tulleken advised. High-risk foods for food poisoning if improperly stored include leftover pizza, risotto, burritos, fried rice, and half a tin of baked beans, according to Dr Primrose Freestone. Cooked chicken is highly perishable once cooled due to its high water and nutrient content and low acidity, favoring bacterial growth, and should be refrigerated within two hours, Dr Freestone said.
Specific risks with leftover pizza involve contaminated ingredients. Dried herbs and spices on pizza, such as basil, pepper, and oregano, can be contaminated with pathogens like Salmonella, Bacillus cereus, and Clostridium perfringens, even after cooking, Dr Freestone explained. Leftover pizza should be refrigerated within two hours of delivery and eaten within two days to avoid bacterial growth, she advised.
Food poisoning can be caused by pathogenic bacteria, fungi, or viruses contaminating food, including through improperly stored leftovers, Dr Freestone said. Unknowns persist regarding fridge safety and food storage guidelines. It is unclear what specific 'completely incorrect' defrost method is widely used, as mentioned by Dr van Tulleken.
The exact number of deaths annually in the UK directly attributable to fridge-related food poisoning, beyond the 'few dozen' mentioned, has not been confirmed. Recent studies or data on the prevalence of bacterial contamination in dried herbs and spices sold in the UK are not detailed in available reports. Recommended storage times for other high-risk leftovers like risotto, burritos, and fried rice beyond general guidelines remain unspecified.
The effectiveness of built-in digital thermometers in new fridges compared to standalone fridge thermometers in preventing food poisoning is not fully established.