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
Microtechnology industry is hiring – positive developments of past years continue
09.04.2018 | IVAM Fachverband für Mikrotechnik
RWI/ISL-Container Throughput Index with minor decline on a high overall level
20.03.2018 | RWI – Leibniz-Institut für Wirtschaftsforschung
Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.
"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...
A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.
Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...
Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.
An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...
Graphene is considered a promising candidate for the nanoelectronics of the future. In theory, it should allow clock rates up to a thousand times faster than today’s silicon-based electronics. Scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) and the University of Duisburg-Essen (UDE), in cooperation with the Max Planck Institute for Polymer Research (MPI-P), have now shown for the first time that graphene can actually convert electronic signals with frequencies in the gigahertz range – which correspond to today’s clock rates – extremely efficiently into signals with several times higher frequency. The researchers present their results in the scientific journal “Nature”.
Graphene – an ultrathin material consisting of a single layer of interlinked carbon atoms – is considered a promising candidate for the nanoelectronics of the...
03.09.2018 | Event News
27.08.2018 | Event News
17.08.2018 | Event News
19.09.2018 | Life Sciences
19.09.2018 | Physics and Astronomy
19.09.2018 | Information Technology