Botulism in fish
Fish products are a source of highly digestible natural protein, phosphorus, calcium, essential omega-3 fatty acids. In the period of intense mental activity, this product is preferred by many students. About its positive effect on the human body can talk for hours. Everyone is good fish, provided that her meat is not contagious.
Just one small piece of fish, struck by botulism (Clostridium botulinum) and about well-being can be forgotten for a long time. Which foods are the most dangerous? What to guide when choosing fish products?
How the fish becomes contagious botulism
In Russia botulism was described in the XIX century under the name "Ichthyism" and associated the disease with the use of fish dishes. But botulism in fish, as well as in meat of herbivores, appears with the use of contaminated water or food. Often the source of infection is a dead animal, as cadaver is an ideal breeding ground for botulinum pathogens.
After entering the water, clostridia are more often found in the ooze, from where they enter the fish's body. That is, herbivorous fish is often the source of infection. Carnivorous animals are resistant to this microorganism and only in exceptional cases are prone to infection.
What kinds of fish do Clostridium live in?
Not only water vertebrates themselves are the source of the most serious infection. Botulism in the sea fish, can, with the same probability, meet, as in the river and lake, if it was caught after catching from the outside. In this case, the source of infection can be:
- lack of proper cooking technology;
- if it is bad to wash the fish or cook it with dirty hands;
- In rare cases, contact with an animal infected with clostridia is possible.
So, many cases of infection with botulism, which is found in canned fish, are known. At the same time, only one bank was the source of infection. This is usually a home-made fish, cooked with the addition of spices in its own juice.
Despite different sources of infection, scientists have identified some species of fish that are most often infected with the infection. These include:
However, other species are also prone to infection. So, the case of botulism is known after the use of whale meat in Alaska.
It happens, infection is not some kind of fish, and improperly cooked, often at home. The source of botulism infection is dried products, purchased not in the store, but in the market. In industrial production, the meat of aquatic vertebrates undergoes rigorous testing and serious selection. At home, these conditions can not be fully respected.
How to distinguish a fish infected with botulism
Any sick animal is easy to distinguish from a healthy one. Herbivorous mammals become sluggish, their gait is disturbed, movements change. But not in the case of fish - it is impossible to keep track of it, no one will observe the behavior of these animals in the river or the sea, therefore it will often be necessary to follow the general principles of the correct choice of a product (usually already killed).
Botulism is also found in smoked products, so try to buy it not on the market for dubious vendors, but in specialized stores that are better tested. If there is atypical smell of smoked product - do not buy.
Reproduction of clostridia in the animal begins at a temperature of 25-35 ° C. If the fish was kept in this temperature range for at least some time, it is better not to take it.
A fresh infected product, like any infection, immediately begins to smell unpleasant.
Characteristic signs of botulism in fish - it is covered with mucus, her eyes are cloudy.
How to avoid botulism in fish
To avoid possible infection, you must choose the right fish and exactly observe the conditions of cooking from it.
- Dirty fish are more likely to be infected with clostridia, make sure that the product you purchased is clean, thoroughly wash it before cooking, cleanse from internal organs.
- Spore forms of clostridium can withstand a temperature of 6 ° C, so when choosing to try to give preference to frozen products. Or, freeze it in the freezer for a few days after purchase.
- Another way to avoid botulism in fish - if you are already buying a ready-made dish, try to take it with a minimum amount of spices, - for an abundance of fragrant herbs may initially hide the spoiled products.
- The vegetative forms of clostridia die at a temperature of 60 ° C, and the spores survive 100 ° C for up to 30 minutes. Try to cook for a long time at high temperature.
For domestic harvesting, the fish should be fresh, well washed. If it is salted - the minimum salt content is 18%, with less quantity harmful microorganisms do not perish.
- Can be preserved only after full treatment. If after opening in the bank there is mold or an unpleasant smell - do not risk your health, throw it away.
No one will give a 100% answer about the species of fish with which the origin of botulism is primarily associated. Marine and freshwater - are equally susceptible to infection with this infection when eating foods containing clostridia. But in order to protect yourself and your relatives from botulism, you need to pay attention to the fact that you buy and observe the above-mentioned conditions of preparation.