You’ve surely heard the expression about one bad apple spoiling the whole bunch. While it’s a metaphor for someone whose behaviour makes a whole group look bad, it might also literally refer to the actual fruit and veg in your fridge.
When you find one rotten grape in a pack or mouldy pepper in your bottom drawer, is the produce touching these items still safe to eat? Or should you throw everything away?
“While one rotten apple can spoil the bunch, it takes time to do so,” says Matt Regusci, director of growth and public relations at ASI, a company that provides food safety inspections, certifications and consulting. “There’s no need to dump the whole vegetable drawer because of one rotten piece of fruit or veggie – just throw out the produce touching the rotten item.”
It’s also likely safe to eat produce that has touched a mouldy item, as long as you wash it first and eat it quickly, he added. But there are many factors to consider. Here’s what you should know about how spoiled produce can affect nearby items and how to decide whether it’s still OK to eat.
Can rotten or mouldy produce contaminate other items?
There are hundreds of thousands of species of moulds, which are microscopic fungi that live on plant and animal matter, according to the US Department of Agriculture. Mould commonly spreads by releasing spores into the air, said Vanessa Coffman, director of the Alliance to Stop Foodbourne Illness. It can also spread via water or insects.
So, mould can easily migrate from one piece of fruit or vegetable to another that’s touching it, says Tamika Sims, senior director of food technology communications at the International Food Information Council.
“It’s best to first throw away the mouldy produce and inspect the produce touching it for mould,” she said. “If you see mould, feel mushy skin or see discolouration, this produce must also be discarded.”
And, “clean out and wipe down your fridge regularly,” especially if you’ve had mouldy items, Coffman adds.
Some moulds are OK to eat, like in blue cheeses, Coffman says. Others can cause severe disease. A few moulds can produce mycotoxins, which are toxins that make you sick, but most consumers aren’t usually exposed to these kinds of moulds, she adds.
Mouldy foods may also have bacterial growth. It’s this bacteria, not the mould itself, that usually causes foodbourne illness, Coffman says
Should you throw away fruits and vegetables that have touched a rotten item?
Food waste is a huge problem in 2022. The average US household wastes 32% of the food it purchases, costing consumers $240bn a year, according to research published in the American Journal of Agricultural Economics.
Meanwhile, in the UK, we throw away 6.6 million tonnes of household food waste a year, according to the climate action NGO, WRAP. That’s almost three quarters is food we could have eaten
So, it’s not always necessary to throw away everything in your bottom fridge drawer or an entire package of strawberries just because you spot one mouldy piece of produce, Coffman says.
It can take a few days to a couple of weeks for fruits and vegetables to grow mould in the refrigerator or pantry, according to the Ultimate Mould Guide.
But if you do see a mouldy item, inspect neighbouring fruits and vegetables for signs of mould (green or white fuzz) or spoilage (mushy texture or discolouration), Sims says.
“Evolution has given humans amazing instincts to tell if food is safe to eat,” using sight, touch and smell, Regusci says. “First, does it look good? No mould or cracks. Does it smell good? Not funky, unless you have purposely fermented or pickled it. Does it feel right? Not super mushy. Then it should taste right.”
Is it safe to eat produce that’s had a mouldy neighbour?
Don’t see mould growing on a fruit or vegetable that’s been hanging out with a mouldy item? You can usually wash the produce under running tap water (avoiding soap) and eat it later. The USDA recommends washing produce under running tap water and avoiding using soap or detergent.
“The likelihood of getting ill from one of the fresh items that have been touching a rotten one is low, especially if you are a person without underlying health conditions,” Coffman says. People with mould allergies or compromised immune systems could be at risk for illness, though.
The USDA mostly recommends throwing away foods that display mould but suggests some foods can still be eaten if you remove the mould.
For example, on firm fruits and vegetables with low moisture content, like cabbage, bell peppers and carrots, you can cut off at least an inch around and below a small mould spot. Just avoid touching the mouldy spot with your knife so you don’t cross-contaminate the produce.
However, soft produce with high moisture content, like tomatoes, peaches and cucumbers, should be thrown away if they show mould.
Coffman said mould on the surface can mean the “mould has also rooted deeply below.” If the food is contaminated with a mycotoxin-producing mould, the toxins spread throughout the item.
Never sniff mouldy items, as you could inhale the mould spores, which could cause respiratory illness. People can also get sick from skin contact with mouldy foods, Coffman says.
Keep in mind, too, that just because the food looks OK or you’ve removed the mouldy bits, it could be unsafe to eat. Pathogens, like e.coli, listeria and salmonella, aren’t visible to the naked eye.
“There isn’t much you can do when inspecting produce at the grocery store to tell if it’s harbouring something that might make you sick,” Coffman says. “What you can do is wash your produce, cook it when possible and keep an eye out for recalls and public health notices.”
She also suggests keeping raw meats and other foods from cooked foods, washing your hands frequently while cooking and handling food, and placing a kitchen thermometer in the refrigerator to ensure it’s set at or below 40 degrees Fahrenheit to keep moulds and bacteria from growing.
“If you do end up accidentally eating something mouldy and have an allergic reaction, seek medical help,” Coffman says. “Symptoms can include a sudden onset of shortness of breath, nausea, fever or diarrhoea.”