Moldy fruit – should you remove the moldy parts or toss it?

Who has not experienced moldy fruit yet: You buy a bowl of raspberries or strawberries but as soon as you want to eat them and take them out of the fridge – mold! What do you do with the whole pack? Should you really throw the whole content away? Or is it sufficient to remove that one moldy berry? Find out everything about the annoying mold that infests our fruit and other foods.

raspberries

Yesterday it happened again: In full anticipation I had bought a bowl of raspberries. In the grocery store they looked nice and fresh. But once I took the bowl out of the refrigerator the next day and opened it with enthusiasm, white mold hairs and green spots jumped right into my face. I wondered whether I should just throw away the few raspberries that were decorated with the mold (after all, it would be a pity to throw all the raspberries away) or whether my overly cautious common sense should take over and wistfully dispose of the entire bowl. “Caution is the mother of the porcelain box” we say in Germany, which translates to “better safe than sorry”, so I decided for the latter and threw the whole bowl into my trash reluctantly. However, was this really necessary?

What exactly is mold and what happens when you ingest it?

In order for mold to grow and thrive, certain conditions are required. These include a certain temperature and pH value as well as the presence of water, carbohydrates, organically or inorganically bound nitrogen, and animal or vegetable fats. This is a long list, but unfortunately our food often meets all these requirements. 

outer mold

The tricky thing is that mold is not always visible to the naked eye. Mold does not only grow on the surface of the food but also inside, where it spreads accordingly. What we can recognize as mold, once it leaves white and green traces on our food, is only the so-called fruiting body of the fungus. This part is the spore carrier which spreads its microscopically small mold spores through the air – you could compare it to the blossom of a flower.

inner mold

The rest of the fungus consists of a rather invisible network (called hyphae) inside the food – this is especially the case with porous food such as bread. Thus, the actual amount of the mold toxins present cannot always be estimated from the visible mold growth. In addition, mold toxins cannot simply be „boiled off“ because they are stable to heat. Hence, if you feel safe through boiling or roasting, you are unfortunately mistaken. Once the food has been attacked by mold, freezing it also no longer helps. 

Mold and human health

The mold produces certain metabolic products, which are called mycotoxins. It is exactly these products which can cause health problems when consumed. Molds which attack nuts, spices and dried fruits are considered to be particularly harmful to our health. With the mold infestation aflatoxins are released, which are cell-damaging carcinogens. The repeated ingestion of smaller amounts of aflatoxins has been associated with liver and kidney damage, can promote liver cancer, as well as change the genetic material. The intake of this so-called „nut mold“ can also lead to acute liver failure. 

Mold and animals

By the way, mold is not only harmful to human health, but also to animals!

If one (or an animal) consumes moldy products, a so-called mycotoxin poisoning can occur. This becomes noticeable through digestive problems such as loss of appetite, diarrhoea, and vomiting. However, it can also have more serious consequences, such as liver or kidney damage, damage to the central nervous and immune system, or damage to the skin and mucous membranes. Long-term effects may even include damage to the genetic material, which can also affect an embryo in the womb, and cause cancer. 

strawberries can get moldy easily

So what do you do with moldy food? How can mold be prevented?

Storage:

  • If you buy fresh food, like fruit, try to process and consume it as soon as possible
  • Pay attention to how you store your food in the refrigerator. For example, strawberries stay fresh longer if you keep them spread out flatly on a plate in the refrigerator.
  • If you discover moldy food, dispose of it immediately since mold spores can spread in the refrigerator.

Mold in the bread box:

  • Clean your bread boxes regularly – old bread crumbs are susceptible to mold and can spread accordingly.
  • If your bread is moldy on one corner, it is recommended for your health to throw away the whole loaf of bread, for the sake of your health. The mold spores may have already spread inside the bread even if they are not visible to the naked eye.

Moldy nuts, dried fruit or spices:

  • If nuts taste funny, the rule applies: Better spit than swallow!
  • Spoiled dried fruit should be disposed of directly. 
  • Do not keep your spices too close to the stove – the heat and humidity that develops favors mold growth. 
  • Mold in spices is difficult to detect as they are often ground very finely. So check your spices’ expiration date regularly.

Moldy jams and jellies:

  • Jams and jellies should always be kept in the refrigerator – the less sugar they contain, the more susceptible they are to mold. 
  • If you find mold in the jam jar, the whole jar should be thrown away. This is because the mold is most likely not only where you can already see it but also on other spots in the jar.

Moldy dairy products:

  • Watery foods are susceptible to mold growth. If you have moldy dairy products, such as milk, yogurt, quark, or cream cheese, they should be thrown away immediately – mold spreads very quickly in and on these products.

Moldy fruit or vegetables:

  • Moldy fruit or vegetables should be disposed of completely. 
  • For fruther processing, for example into compote, moldy fruit or vegetables are also not suitable. The toxins cannot be destroyed by cooking or similar processes and remain in the processed product.
moldy cheese

But mold is not equal to mold

Not every mold is harmful to our health. Sometimes mold is even intentional, for example when it comes to certain types of cheese or sausage. This mold is called „edible culture“ or „edible mold“, has no negative effects on our health and can be consumed without any risk. Noble mold provides a unique smell and taste as in the case of salami or blue cheese, for example. One should therefore not confuse this edible mold with the unwanted, harmful mold.

Animals can also suffer from mycotoxin poisoning

An important note at the end: Please never feed moldy food to animals – they can, as mentioned beforehand, suffer from mycotoxin poisoning just like us humans!

In a nutshell

Moldy food should not be taken lightly. Experts advise that moldy food should always be thrown away when in doubt. Better safe than sorry! Even if we can only recognize small mold stains on the food, the fungal threads are invisible to our naked eyes and have most likely spread inside the food product already. Sufficient hygiene should be maintained in the refrigerator and in the bread box by cleaning them regularly. Lastly, check your perishable food on a regular basis as well.