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
Mathematical confirmation: Rewiring financial networks reduces systemic risk
22.06.2017 | International Institute for Applied Systems Analysis (IIASA)
Frugal Innovations: when less is more
19.04.2017 | Fraunhofer-Institut für Arbeitswirtschaft und Organisation IAO
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
20.11.2017 | Earth Sciences
20.11.2017 | Physics and Astronomy
17.11.2017 | Physics and Astronomy