A microbiologist has set out where fruit and vegetables should be stored to keep them fresh for up to six weeks, arguing that use-by dates are not always a reliable guide.
Dr Primrose Freestone, a microbiologist at the University of Leicester, wrote in an article for The Conversation that the environment produce is kept in can affect its shelf life. "The environment fresh produce is stored in can affect the shelf-life of produce - so use-by dates may not always be accurate," she explained.
"Fruit and veg are living - so things like humidity, temperature, atmospheric gas, light, how long it's been in storage and any potential microbial contamination can all affect how long produce can be stored."
Fruit
Dr Freestone advises keeping apples in the fridge rather than a fruit bowl. "Apples have a shelf-life of around one week at room temperature, and three to four weeks in the fridge," she said. "These should ideally be stored in the fridge's veg drawer and washed before eating."
Berries also last around a week if refrigerated, but Dr Freestone warned against eating any if even one in the punnet shows mould. "Even if only one berry in the punnet has mould and the rest look fine, they may still contain mould," she said, explaining that mould toxins called mycotoxins are invisible and can spread to nearby food. "Mycotoxins, such as the Aspergillus aflatoxin, can cause serious damage to the liver and have been linked to liver cancer."
Citrus fruits and grapes also benefit from refrigeration. "Citrus fruits are usually good for around one week at room temperature, and up to one month in the fridge," Dr Freestone said. "Grapes can last several days at room temperature, and up to two weeks when refrigerated."
Bananas, by contrast, can be kept in the cupboard and last up to a week at room temperature depending on ripeness at purchase, though she said they should be kept away from other produce.
"Bananas are high ethylene producers, while apples are even stronger ethylene releasers," Dr Freestone said. "Both can prematurely accelerate ripening of other fruit and veg, which can lead to over-ripeness, spoilage and mould growth. It's therefore a good idea to avoid storing these fruits near other produce."
Vegetables
Carrots and parsnips are often kept in the cupboard, but Dr Freestone said moving them to the fridge is a better choice. "Carrots and parsnips can be stored for up to two weeks in a cool pantry, and for more than a month in the fridge. Just make sure they're stored in perforated bags to allow airflow," she said.
Cucumbers and lettuce should also go in the fridge, along with mushrooms, which have a much shorter shelf life at room temperature. "Mushrooms have a shelf life of only one day at room temperature, and three to seven in the fridge," Dr Freestone said.
Onions and potatoes should be stored in the cupboard, but kept apart from each other. "Onions can sometimes last more than six weeks when stored in a cool, dry, well-ventilated area," Dr Freestone said. "You shouldn't store them with potatoes or other veg that release moisture, as this will cause fungus to grow. Potatoes can also last more than six weeks when stored in a cool, dark, dry place."
