title: Assessment of freshness and freeze-thawing of sea bream fillets (Sparus aurata) by a cytosolic enzyme: Lactate dehydrogenase.
abstract: The evaluation of freshness and freeze-thawing of fish fillets was carried out by assessment of autolysis of cells using a cytosolic enzyme lactate dehydrogenase. Autolysis plays an important role in spoilage of fish and postmortem changes in fish tissue are due to the breakdown of the cellular structures and release of cytoplasmic contents. The outflow of a cytosolic enzyme, lactate dehydrogenase, was studied in sea bream fillets and the Sparus aurata fibroblasts (SAF-1) cell-line during an 8day storage period at +4°C. A significant increase of lactate dehydrogenase release was observed, especially after 5days of storage. The ratio between the free and the total lactate dehydrogenase activity is a promising predictive marker to measure the quality of fresh fish fillets. The effect of freeze-thawing on cytosolic lactate dehydrogenase and lysosomal α-d-glucosidase activities was also tested. Despite the protecting effect of the tissue compared to the cell-line, a loss of lactate dehydrogenase activity, but not of α-d-glucosidase, was observed. In conclusion, lactate dehydrogenase may be used as a marker to both assess freshness of fish and distinguish between fresh and frozen-thawed fish fillets.
authors.affiliation: Univ. Littoral Côte d'Opale, CNRS, Univ. Lille, UMR 8187, LOG, Laboratoire d'Océanologie et de Géosciences, 32 Avenue Foch, Wimereux, France; Université Cheikh Anta DIOP de Dakar, Laboratoire de Toxicologie et d'Hydrologie, BP 5005 Dakar, Senegal. Electronic address: mamedou82@yahoo.fr.
authors.forename: Mamadou
authors.initials: M
authors.lastname: Diop
authors.affiliation: Univ. Littoral Côte d'Opale, USC ANSES, EA 7394 - ICV - Institut Charles Viollette, F-62200 Boulogne sur Mer, France; Univ. Lille, F-59000 Lille, France; Univ. Artois, F-62000 Arras, France; INRA, France; ISA, F-59000 Lille, France. Electronic address: denis.watier@univ-littoral.fr.
authors.forename: Denis
authors.initials: D
authors.lastname: Watier
authors.affiliation: Univ. Littoral Côte d'Opale, USC ANSES, EA 7394 - ICV - Institut Charles Viollette, F-62200 Boulogne sur Mer, France. Electronic address: pierreyves.masson@gmail.com.
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Masson
authors.affiliation: Université Cheikh Anta DIOP de Dakar, Laboratoire de Toxicologie et d'Hydrologie, BP 5005 Dakar, Senegal. Electronic address: amdiouf@refer.sn.
authors.forename: Amadou
authors.initials: A
authors.lastname: Diouf
authors.affiliation: Univ. Littoral Côte d'Opale, CNRS, Univ. Lille, UMR 8187, LOG, Laboratoire d'Océanologie et de Géosciences, 32 Avenue Foch, Wimereux, France. Electronic address: rachid.amara@univ-littoral.fr.
authors.forename: Rachid
authors.initials: R
authors.lastname: Amara
authors.affiliation: Univ. Littoral Côte d'Opale, USC ANSES, EA 7394 - ICV - Institut Charles Viollette, F-62200 Boulogne sur Mer, France; Univ. Lille, F-59000 Lille, France; Univ. Artois, F-62000 Arras, France; INRA, France; ISA, F-59000 Lille, France. Electronic address: thierry.grard@univ-littoral.fr.
authors.forename: Thierry
authors.initials: T
authors.lastname: Grard
authors.affiliation: Univ. Littoral Côte d'Opale, USC ANSES, EA 7394 - ICV - Institut Charles Viollette, F-62200 Boulogne sur Mer, France; Univ. Lille, F-59000 Lille, France; Univ. Artois, F-62000 Arras, France; INRA, France; ISA, F-59000 Lille, France. Electronic address: philippe.lencel@univ-littoral.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Lencel
mesh_terms: D000818:Animals; D005511:Food Handling; D005615:Freezing; D007770:L-Lactate Dehydrogenase / Q000737:chemistry*; D021541:Sea Bream / Q000382:microbiology*
chemical_list: D007770:L-Lactate Dehydrogenase
keywords: Autolysis; Disodium phosphate (PubChem CID 24203); Fish cell lines SAF-1; Fish freshness; Frozen-thawed; Hydrochloric acid (PubChem CID 313); Iodonitrotetrazolium chloride (PubChem CID 64957); Lactate dehydrogenase; Monosodium phosphate (PubChem CID 23672064); Penicillin (PubChem CID 5904); Sea bream (Sparus aurata); Sodium chloride (PubChem CID 5234); Streptomycin (PubChem CID 19649); l-glutamine (PubChem CID 5961)