The black colour seen on the skin is something that most people notice while buying onions. You can see the black colour in many places inside as well once the skin is peeled. Many people wonder if an onion with such black skin is edible. Let's see what the black color seen on onions is and whether it can cause health problems if eaten.

The black spots seen on the skin and inside of the onion are a type of mould. It is known as Aspergillus niger. Although this mold is not dangerous, it is worth paying attention to. The change in temperature causes mould to form on onions. It can cause health problems such as vomiting, nausea, headaches, stomach aches, fungal infection or even allergic reactions.

After peeling the onion, wash it thoroughly and make sure that all the mould is gone before using it for cooking. If the onions have excessive mould and do not come off after washing, it is better to discard them. This is because the microorganisms can create toxic byproducts according to cooking.