title: Effect of freezing/thawing process in different sizes of blue fish in the Mediterranean through lysosomal enzymatic tests.
abstract: The assessment of freshness of different sizes of blue fish (Engraulis encrasicolus 12 cm, Sardina pilchardus 15 cm, Trachurus trachurus 40 cm, Scomber japonicus colias 60 cm) was carried out using non-conventional enzymatic methods. The activities of the three lysosomal enzymes (α-glucosidase (AG), β-galactosidase (B-GAL) and β-N-acetylglucosamidase (B-NA)) in extracts of blue fish muscle were measured over a period of 21 days of storage. A significant increase (p<0.05) of AG activity was observed in all species, with a large increase seen after only one day of storage. B-NA activity increased slightly in sardines, horse mackerels and chub mackerel during frozen/thawed storage. Finally, the increase of B-GAL activity was significant (p<0.05) only in the samples of larger blue fish as horse mackerel and chub mackerel. All of these enzyme activities may be helpful predictive markers to limit fraud in these species.
authors.affiliation: Dipartimento di Scienze delle Produzioni Agrarie e Alimentari (DISPA), Università degli Studi di Catania, via S. Sofia 98, 95123 Catania, Italy. Electronic address: giusialberio@yahoo.it.
authors.forename: Giuseppina R A
authors.initials: GR
authors.lastname: Alberio
authors.forename: Riccardo N
authors.initials: RN
authors.lastname: Barbagallo
authors.forename: Aldo
authors.initials: A
authors.lastname: Todaro
authors.forename: Gioacchino
authors.initials: G
authors.lastname: Bono
authors.forename: Giovanni
authors.initials: G
authors.lastname: Spagna
mesh_terms: D000118:Acetylglucosaminidase / Q000032:analysis*; D000818:Animals; D005399:Fishes / Q000145:classification; D005511:Food Handling / Q000379:methods*; D061353:Food Storage; D005615:Freezing; D008247:Lysosomes / Q000737:chemistry / Q000201:enzymology*; D019083:Mediterranean Region; D009132:Muscles / Q000737:chemistry / Q000201:enzymology*; D017747:Seafood / Q000032:analysis*; D000520:alpha-Glucosidases / Q000032:analysis*; D001616:beta-Galactosidase / Q000032:analysis*
chemical_list: D000520:alpha-Glucosidases; D001616:beta-Galactosidase; D000118:Acetylglucosaminidase
keywords: Blue fish; Commercial fraud; Freeze/thawing; α-Glucosidase (AG); β-Galactosidase (B-GAL); β-N-acetylglucosamidase (B-NA)