Madeline Adams
We particularly like to eat hazelnuts, walnuts and peanuts at Christmas time – or bake them into delicious cookies and Christmas cookies. But how do you know if the nuts are still good and what about bitter nuts? We explain which nuts you should no longer eat.
There is a large selection of nuts: walnuts, hazelnuts, peanuts, macadamias, cashews and Brazil nuts are healthy and delicious snacks. They provide us with proteins, valuable fats, minerals and vitamins. Because of the high fat content and therefore many calories, you should only eat about a handful of nuts a day.
The healthy walnuts, for example, score with the highest content of alpha-linolenic acid, an omega-3 fatty acid. In our walnut test, however, not all products were convincing: Some walnut kernels tasted of packaging, while the laboratory detected mineral oil and a plasticizer in others.
Beware of bitter nuts: there is a risk of mold toxins
In general, nuts are healthy snacks that we should eat every day. However, nuts are not always harmless to health: last winter, the Federal Office for Consumer Protection and Food Safety (BVL) warned against mold toxins in nuts.
If nuts are infested with mould, they can produce the mold toxins aflatoxin and ochratoxin A. Mold toxins (mycotoxins) can form during harvest and transport, but often only during storage.
Mold toxins in nuts are difficult to detect
The BVL warns that mold can lead to diseases in humans that promote the development of cancer, damage the kidneys and liver, impair the immune system or cause diarrhea and vomiting. Unlike some other pollutants, mold is not destroyed by high temperatures during cooking, roasting, or baking.
And not only that: mold toxins in nuts are not visible to the naked eye. According to the Lower Saxony State Office for Consumer Protection and Food Safety, you cannot smell or taste the affected nuts.
How to prevent mold on nuts
So what to do? In any case, you should not eat nuts if you notice dark discoloration, an oily sheen or an unpleasant smell when you open them. Better throw the nuts away.
Even if you encounter an atypical, musty or bitter taste when eating, do not swallow the nut, but spit it out again. Bitter and musty nuts could be infected with mold.
In our walnut test, we were able to give the all-clear: the commissioned laboratory did not find any mold toxins in the 20 cracked and packaged walnut kernels.
In every study by the BVL, it was also noticed that ground nuts were significantly more often contaminated with mold toxins than whole nuts. The differences were particularly large for ground and whole almonds.
Tips for safe nut indulgence:
- Buy whole nuts with their shells: These are less likely to be affected by mold and are often available loose.
- Regional nuts are preferred for shorter transport routes.
- Store nuts correctly: Store whole nuts with their shells in a dry, cool place, preferably in a dark place. It is best to use up crushed or ground nuts quickly and store them in an airtight container in the fridge or freezer.
- Do not eat discolored nuts or bitter, musty nuts.
