7 Genomic Approaches in Aquaculture and Fisheries
239
7.5.5 Seafood Authentication and Traceability
Traceability is increasingly becoming standard across the agri-food industry, largely
driven by recent food crises and the consequent demands for transparency within
the food chain. European citizens are entitled by law (CR-EC No. 2065/2001 and
104/2000) to information on the scientific name, method of production (farmed or
wild), and the area in which wild fish was caught or farmed fish underwent the
final developmental stage. Additional legal requirements for the implementation of
traceability systems in the food and feed supply chains in Europe are laid down in
the General Food Law, Regulation 178/2002/EC, whose article number 18 referring to traceability has become effective since 1st January 2005. The EU Food Law
defines traceability as ‘‘the ability to trace and follow a food, feed, food-producing
animal or substance intended to be, or expected to be incorporated into a food or
feed, through all stages of production, processing and distribution’’ (Martinez et al.
2007).
Traditional analytical techniques which relied on protein analysis have been
developed for fish species identification: electrophoretic techniques such as isoelectric focusing or SDS-PAGE; chromatographic techniques and immunological
techniques such as immunodiffusion and ELISA. Although most of these methods
are of considerable value in certain instances, they are not suitable for routine sample analysis because proteins lose their biological activity after animal death, and
their presence and characteristics depend on the cell types. Furthermore, most of
them are heat labile. Thus, if the product has been subjected to severe processing
conditions (such as sterilization in canning) one has to rely on techniques that target
small DNA fragments. This is because proteins and DNA are altered so much that
they do not render recognizable patterns. For an updated and extensive overview on
the PCR-based methods and the application of proteome analyis to fish and fishery
products authentication please refer to Martinez and Friis (2004), Martinez et al.
(2005) and Gil (2007). An overview of barcoding techniques used in fisheries is
also presented in Chapter 1.
Recently, it became clear that to ensure a validation of the authentication methodologies and specifically when using DNA based techniques, quantifiable reference
materials in the form of plasmids needed to be developed. In the framework of
the EU SEAFOODPlus project, a pool of plasmidic standards has been prepared
as reference materials for usage in DNA techniques for fish authentication. An
Interlaboratory Ring Test, involving 12 research centres and institutions having
genetic fish identification services and offering authentication analysis to fish industry, has been used to validate such standards. This development has been submitted
for a patent application. At the same time, a dynamic DNA database including more
than 700 DNA sequences from 53 commercial fish species has been made accessible free by internet (http://www.azti.es/DNA_database). Several commercial kits
for fish species identification already exist in the market and show potential for field
screening purposes in inspection programs (Gil 2007).
Although still in its infancy, a growing global gene expression profiling at the
mRNA or protein level is undoubtedly providing us with a better understanding
239
7.5.5 Seafood Authentication and Traceability
Traceability is increasingly becoming standard across the agri-food industry, largely
driven by recent food crises and the consequent demands for transparency within
the food chain. European citizens are entitled by law (CR-EC No. 2065/2001 and
104/2000) to information on the scientific name, method of production (farmed or
wild), and the area in which wild fish was caught or farmed fish underwent the
final developmental stage. Additional legal requirements for the implementation of
traceability systems in the food and feed supply chains in Europe are laid down in
the General Food Law, Regulation 178/2002/EC, whose article number 18 referring to traceability has become effective since 1st January 2005. The EU Food Law
defines traceability as ‘‘the ability to trace and follow a food, feed, food-producing
animal or substance intended to be, or expected to be incorporated into a food or
feed, through all stages of production, processing and distribution’’ (Martinez et al.
2007).
Traditional analytical techniques which relied on protein analysis have been
developed for fish species identification: electrophoretic techniques such as isoelectric focusing or SDS-PAGE; chromatographic techniques and immunological
techniques such as immunodiffusion and ELISA. Although most of these methods
are of considerable value in certain instances, they are not suitable for routine sample analysis because proteins lose their biological activity after animal death, and
their presence and characteristics depend on the cell types. Furthermore, most of
them are heat labile. Thus, if the product has been subjected to severe processing
conditions (such as sterilization in canning) one has to rely on techniques that target
small DNA fragments. This is because proteins and DNA are altered so much that
they do not render recognizable patterns. For an updated and extensive overview on
the PCR-based methods and the application of proteome analyis to fish and fishery
products authentication please refer to Martinez and Friis (2004), Martinez et al.
(2005) and Gil (2007). An overview of barcoding techniques used in fisheries is
also presented in Chapter 1.
Recently, it became clear that to ensure a validation of the authentication methodologies and specifically when using DNA based techniques, quantifiable reference
materials in the form of plasmids needed to be developed. In the framework of
the EU SEAFOODPlus project, a pool of plasmidic standards has been prepared
as reference materials for usage in DNA techniques for fish authentication. An
Interlaboratory Ring Test, involving 12 research centres and institutions having
genetic fish identification services and offering authentication analysis to fish industry, has been used to validate such standards. This development has been submitted
for a patent application. At the same time, a dynamic DNA database including more
than 700 DNA sequences from 53 commercial fish species has been made accessible free by internet (http://www.azti.es/DNA_database). Several commercial kits
for fish species identification already exist in the market and show potential for field
screening purposes in inspection programs (Gil 2007).
Although still in its infancy, a growing global gene expression profiling at the
mRNA or protein level is undoubtedly providing us with a better understanding