Botulism is a serious form of food poisoning that can even be life-threatening. We tell you how botulism develops and how you can protect yourself from it.
Botulism is caused by the neurotoxin botulinum toxin. This toxin is caused by the bacterium Clostridium botulinum, which is particularly resistant to heat and cold. Botulism is not to be trifled with: in the worst case, this food poisoning can be fatal. Luckily, botulism is very rare.
Botulism: symptoms and diagnosis
Botulism can manifest itself through the following symptoms:
- dry mouth
- nausea
- Vomit
- Diarrhea
- circulatory problems
- Signs of paralysis in the eye and throat muscles
- numbness in the hands
In severe cases, the paralysis spreads from the head.
There are antidotes that can be used to combat the symptoms. However, diagnosing botulism is not easy because it is such a rare phenomenon. If you suspect botulism, be sure to tell your doctor if you ate canned or preserved food before the onset of symptoms. Thanks to improved laboratory technology, it is now possible to detect toxins in stool samples within a few hours.
Botulism from cooked foods
The bacterium Clostridium botulinum occurs frequently in nature: It can be found in soil and water. That is why it can also get into our food. The name already suggests this: botulism comes from the Latin word botulus, which means “sausage”. The causative bacterium was first detected in a ham in 1896.
However, not only meat products are affected – the bacterium can also occur in preserved and particularly protein-rich foods. Canned foods and jars provide the perfect environment for the bacteria to multiply and produce botulinum toxin. To do this, it must be shielded from oxygen. Although the bacterium and the resulting toxins can be destroyed by heat, the contents of an infested can are often not heated to the required 80 degrees.
In the past, botulinum neurotoxins were often found in bloated tin cans. In the 19th century, seafarers in particular often contracted botulism during their long voyages because they ate the contents of the bloated cans for lack of alternatives. Since the neurotoxin botulinum toxin is colorless and odorless, the danger is not so easy to recognize.
In the past, however, canned goods were processed much less cleanly than they are today and botulism could easily form in the absence of air. In the meantime, this danger usually only exists if you cook it yourself. You should be particularly careful with beans, mushrooms and asparagus, as they contain a lot of protein. With other preserves like jam, on the other hand, the risk of botulism is almost impossible.
Avoid botulism: this is how you cook properly
Canning is a great way to stock up and preserve food. Nevertheless, the process is not entirely harmless because of the risk of botulism. However, to protect yourself from botulism while preserving, you just need to take a few precautions. It is particularly important that you pay attention to hygiene and boil the canned food long enough to kill the bacterium. You should follow these rules to protect against botulism when cooking:
Thoroughly boil all canning supplies, such as jars, lids, and sealing rings, for at least 10 minutes before using them. This will sterilize the jars. Wash your hands and work surface thoroughly, too.
You should also clean the food you want to preserve well. If you discover moldy areas, it is better not to process the affected specimen further. Also check carefully whether there are other moldy specimens.
Fill the jars and close them tightly. Boil the sealed jars in a large saucepan for 2 hours. When cooking on the stove, you reach a temperature of 100 degrees.
Repeat the cooking process again after 24 hours. This will destroy any germinated spores.
If you have a pressure cooker, use it to cook. If you work with a pressure cooker, the temperatures during cooking are between 116 and 119 degrees. So you can be sure that all bacteria will be killed. The higher temperatures are caused by the pressure that is created in the pressure cooker. This also reduces the cooking time to 25 minutes.
Don’t eat canned foods that have obviously been improperly stored. This is the case, for example, when the lid has opened. The same applies to bloated canned goods.
Never eat cooked food unheated. This is especially true for vegetables that are particularly rich in protein – for example beans. Before you eat preserves, you should heat them up to 80 degrees for at least five minutes. This will destroy any poison that may be present.
If you follow these safety rules, the risk of contracting botulism is extremely low.
