(AG / 12-07-10) A new method discovered by Spanish scientists can detect anisakis parasite in all sorts of fish, from an entire specimen, fresh or frozen, to canned and “surimi”, processed fish sticks that gives colour and flavour to our dishes.
The method is based on molecular techniques and it is a fast and efficient method that can detect parasite in fish although it appears in very low quantities (0.05pg), according to Montserrat Espiñeira, one of the researchers in the area Molecular Biology and Botechnology of ANFACO-CECOPESCA. The results of the study have been published in the last number of the magazine Food Control.
Methods used up to now for anisakid larvae detection were visual examination, the traslumination and digestion by artificial gastric juice. These traditional systems did not allow to analyze very big species or being applied to processed products.
Presence in marine species and human being
Anisakid belong to the family 'Anisakidae' and species with greater involvement in parasitic infections in humans are 'Anisakis simplex' and 'Pseudoterranova decipiens'.
Anisakis larvae parasitize the muscle tissue and viscera of many species and cephalopods that live mainly in cold waters. Among others, they can be found in cod, hake, mackerel, sardines, anchovies, salmon, herring, tuna, whiting, turbot, cuttlefish or squid.
The human being is only an accidental host of anisakis. When infested fish is eaten raw, marinated or undercooked, the larvae can pass to humans and cause infection anisakiosis. Clinical signs that are abdominal pain, nausea, vomiting and diarrhoea, as well as possible allergic reactions.
Situation in Spain
In 1991 the European Union adopted the first measures to prevent anisakiosis. The trend of consuming fish raw, dried, marinated, etc. in Spain is the cause of the increase in these gastrointestinal infections.
The Ministry of Health of Spain reminds that anisakis larvae are sensitive to heat, temperatures of 55º C or 60º C. This means that products fully cooked (boiled or fried), hot-smoked and pasteurized foods are safe from the point of view of inactivation the parasite. On the other hand, if it is going to be eaten raw it should be frozen more than 24 hours at -20º C as a precaution.
