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
Scientists at the Fraunhofer Institute for Laser Technology ILT have come up with a striking new addition to contact stamping technologies in the ERDF research project ScanCut. In collaboration with industry partners from North Rhine-Westphalia, the Aachen-based team of researchers developed a hybrid manufacturing process for the laser cutting of thin-walled metal strips. This new process makes it possible to fabricate even the tiniest details of contact parts in an eco-friendly, high-precision and efficient manner.
Plug connectors are tiny and, at first glance, unremarkable – yet modern vehicles would be unable to function without them. Several thousand plug connectors...
An international research team has found a new approach that may be able to reduce bone loss in osteoporosis and maintain bone health.
Osteoporosis is the most common age-related bone disease which affects hundreds of millions of individuals worldwide. It is estimated that one in three women...
Traditional single-cell sequencing methods help to reveal insights about cellular differences and functions - but they do this with static snapshots only...
“Core-shell” clusters pave the way for new efficient nanomaterials that make catalysts, magnetic and laser sensors or measuring devices for detecting electromagnetic radiation more efficient.
Whether in innovative high-tech materials, more powerful computer chips, pharmaceuticals or in the field of renewable energies, nanoparticles – smallest...
An international research team with Prof. Cornelia Denz from the Institute of Applied Physics at the University of Münster develop for the first time light fields using caustics that do not change during propagation. With the new method, the physicists cleverly exploit light structures that can be seen in rainbows or when light is transmitted through drinking glasses.
Modern applications as high resolution microsopy or micro- or nanoscale material processing require customized laser beams that do not change during...
23.07.2020 | Event News
21.07.2020 | Event News
07.07.2020 | Event News
06.08.2020 | Earth Sciences
06.08.2020 | Power and Electrical Engineering
06.08.2020 | Life Sciences