The results show that 24.4% of the labels display the wrong species name, and that information is incomplete in 39% of cases. The researchers have patented a molecular method that enables this type of shellfish species to be distinguished by its mitochondrial DNA.
The researcher and professor at the Laboratorio de Higiene, Inspección y Control de Alimentos (LHICA) (Laboratory for Hygiene, Inspection and Monitoring of Food), at the Spanish Council for Scientific Research (USC), Jorge Barros, who is managing the project, explains to SINC that the morphological differentiation between crustaceans "is not easy, and is more or less impossible to achieve in the peeled product. This makes it difficult for both people working in the industry and consumers to be sure that the labelling is correct". In fact, some companies resort to a "generic" labelling system, simply naming them "langoustines" or "prawns" without specifying the marketed species, "probably because they do not have reliable methods available to identify the marketed species".
However, each species has its own organoleptic properties, which determine their price and commercial value, Barros explains. "In Japan they will even pay 100 dollars per kilo for certain types of langoustines", he adds, "for which reason if there is a methodology available that enables the species to be determined this could be very useful for both the industrial sector and the authorities too".
In order to carry out the study, langoustines or prawns used as commercial ingredients and other pre-cooked products were analysed. In order to compare results, a collection of reference species was used as a referencemarker and was set up with the co-operation of Julio Maroto, a researcher from the Centro Tecnológico del Mar (CETMAR) (Marine Technology Centre) in Vigo, and marine biologists from the CSIC (Spanish National Research Council).
A new molecular method for differentiating between langoustines
The authentication method developed by the Galician scientists has been patented and published in the Electrophoresis journal and enables more than 20 species of langoustine to be differentiated by using DNA mitochondrial analysis. To differentiate between them, the 16S gene sequence is analysed (this codifies the long mitochondrial ribosomal RNA) and the gene sequence that codifies the valine amino acid RNA transfer, although the scientists have already started studying the importance of other markers, such as mitochondrial cytochrome b and cytochrome-oxidase.
The results obtained confirm that in Spain, a large variety of whole or processed langoustine species is marketed under the format of 2pre-cooked dishes ingredients". Furthermore, this methodology enables the degree of relationship or phylogenetic relationships between this type of crustacean to be studied.
In addition, the researchers have developed a specific technique for determining the two species having the greatest commercial impact: the giant tiger prawn (Penaeus monodon) and the Pacific white shrimp (Litopenaeus vannamei). Both species come from aquaculture farms in Central American countries or from South-East Asia, and represent almost 80% of the total volume of farmed langoustines marketed world-wide.
The researchers from the Institute of Marine Research, CSIC, headed by scientist José Manuel Gallardo, have made advances in the definition of species differentiation markers. They are also studying certain allergenic proteins in langoustines, such as tropomyosine, with a view to designing immunological methods to make it possible to detect and identify these in foodstuffs.
SINC Team | alfa
Preferential trade agreements enhance global trade at the expense of its resilience
17.02.2017 | International Institute for Applied Systems Analysis (IIASA)
How Strong Brands Translate into Money
15.11.2016 | Kühne Logistics University - Wissenschaftliche Hochschule für Logistik und Unternehmensführung
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
21.02.2017 | Earth Sciences
21.02.2017 | Medical Engineering
21.02.2017 | Trade Fair News