When we talk about anisakis, most of us think about being careful with sushi, the quintessential raw fish dish. However, pickled anchovies are the main source of infection, since vinegar does not kill anisakis.
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Did you know that 9 out of 10 people who contract anisakis do so after consuming pickled anchovies? And it is that vinegar does not kill anisakis . So pickled anchovies and other marinated pickled fish may contain anisakis if we have not previously frozen it.
We can rest assured that the pickled anchovies cover of any bar or restaurant is safe. Also those that we can buy already prepared. These establishments are obliged to follow certain security measures regulated by law. The problem lies, rather, in those of us who can cook at home.
In recent years, the food industry has had exponential growth. Globalization and the large circulation of goods have brought us into contact with multiple agents that can cause allergies . One of these possible allergens is anisakis.
Anisakis: what is it and how does it affect us?
Anisakis ( Anisakis simplex ) is a parasite that is about 2 centimeters long. Their larvae live in the digestive system of many marine species and in some crustaceans.
Humans can become infected with anisakis only after consuming raw or undercooked contaminated fish . Larvae penetrate the intestinal mucosa layer and can cause anisakiasis.
This acute form of the disease is usually transient and lasts for a few weeks. Then it is eliminated through the faeces.
Some of its symptoms are:
- Abdominal pain.
In addition, anisakis can also involve immunoglobulin E mediated allergic reactions , which could cause us from hives to asthma or anaphylaxis in cases of high sensitivity. However, on many occasions the parasite will pass without leaving more problems than those typical of food poisoning .
Symptoms of anisakis disease are typical of gastroenteritis
How to avoid anisakis?
Now that we know that vinegar does not kill anisakis, let’s see what measures we must take into account to avoid poisoning:
- Buy the fish already clean and without guts. If it cannot be, we must do it ourselves as quickly as possible.
- Anisakis can be removed by temperature. If we want to consume raw fish, we must freeze it At less than 20 ºC and for at least 5 days. If this temperature cannot be guaranteed – in 3-star refrigerators, yes – you must buy the frozen fish.
- The safe cooking methods are baking, grilled or fried at 60ºC for at least 1 minute. Ensuring that the heat reaches the entire piece equally. The same can be done with shellfish, grilled or cooked.
- When the fish pieces are very large, this temperature should be kept around 10 to 12 minutes.
Find out more: Poorly cooked foods: can they be bad for your health?
Active ingredients against anisakis
While the measures seen above serve to prevent infection with anisakis, various ways are being studied, apart from frozen, to be able to eliminate it from fish.
The purpose is to eliminate it, without affecting the organoleptic quality of the food, since the texture may be affected by freezing. Some of them are the application of high hydrostatic pressure, vacuum suction or electrocution.
At the same time, some active ingredients are known that can destroy the larvae. Soy sauce or wasabi have been traditionally used in oriental cuisine.
Also some essential oils like perilla have this property. Although it is ginger ( Zingiber officinale ) that at the moment is obtaining the most promising results.
In a 2015 study, it is concluded that:
“Ginger has effective antiparasitic activity against various parasites and can be used for the prevention of drug-resistant parasitic diseases. However, further evaluation is necessary to isolate the active components and determine their toxicity, side effects and pharmacokinetic properties. ”
The most sensitive dishes to contain anisakis
Ginger may be helpful in inactivating anisakis, according to some scientific studies
If we want to be calm when eating raw or undercooked fish, we must freeze the fish before preparing the following dishes:
- Anchovies in vinegar and other pickled fish.
- Sushi, sashimi or carpacio.
- Marinated fish, as in the case of ceviche.
- Raw or practically raw fish roe.
- Herring and other raw fish prepared in brine or slightly salted.
- Marine fish subjected to cold smoking.
This will not be necessary in the case of preserves such as packaged anchovies, freshwater or farmed fish, and dried fish salted in the traditional way, such as cod. Nor in the case that we buy the most sensitive preparations already packaged.
Read more: 9 foods you shouldn’t store in the freezer
Vinegar does not kill anisakis, but we can freeze the fish
Most helminth infections are caused by anisakis. Poisonings can cause a wide range of symptoms, from mild to severe allergic reactions.
At the moment, the safest method of avoiding poisoning is to freeze for 5 days all fish that you want to eat raw. And in fish recipes, cook it at least 60ºC for about 10 minutes.