Genetic help to the separation of fish

2002/12/04 Andonegi Beristain, Garazi - Elhuyar Zientziaren Komunikazioa

• Industria
• Dietetika/Elikagaiak
• Ikerketa-zentroak

The work presented by AZTI corresponds to a new line of research that serves to identify itself after the processing of food and fishing products. In response to the demand for this type of research, AZTI has received support from the Basque Government's Department of Fisheries and Agriculture to create a new genetics laboratory.

In fact, genetic studies have been considered in recent times as a tool of great capacity, not only for the identification of species but also for the identification of races, varieties and populations within species. The new research is based on the analysis of DNA.

To date, the identification of fresh and processed fish was done through protein analysis. However, this method is not applicable to fish preserves that suffer treatments of long duration and high temperature. These thermal treatments and the sterilization that is applied below transform the proteins of food, so they cannot be used as molecular markers of the species.

The identification of commercial species becomes increasingly important in the food industry, on the one hand, to control the raw material used by the companies themselves, and on the other, to avoid fraud in the labeling of processed products. In fact, the verification of the products marketed constitutes at present a serious problem due to the loss of external properties in the processing of the product, which prevents identifying the species. It is estimated that in the world 25,000 marine products and meat products are sold without knowing the species of origin, which means a fraud in the labels.

In the case of fish preserves, due to the hardness of the heat treatment applied to them, DNA also undergoes transformations. Therefore, it is difficult to identify species using genetic techniques, since the parts of DNA extracted are usually relatively small. This is the case of the preserves of Thunnus.

AZTI researchers have developed a genetic marker based on the PCR method, by which the species of the tuna family is identified in the fresh, frozen and processed product. They are now looking for the same objective with the cod family, so they will soon develop the method of identifying more than 10 commercial species of the cod family (gastric).

Link: http://www.basqueresearch.com