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Microbiological Stability of Canned Tuna Produced in Italy and in Non-European Countries

Casalinuovo, Francesco, Gazzotti, Teresa, Rippa, Paola, Ciambrone, Lucia, Musarella, Rosanna, Pratticò, Elena
Italian journal of food safety 2015 v.4 no.1
Acinetobacter, Agrobacterium radiobacter, Alternaria, Bacillus cereus, Bacillus vallismortis, Enterococcus faecalis, Escherichia coli, European Union, Gram-negative bacteria, Gram-positive bacteria, Leuconostoc mesenteroides, Penicillium, Rhizopus, Rhodotorula, Salmonella, Sphingomonas paucimobilis, Staphylococcus aureus, Staphylococcus lentus, Staphylococcus warneri, Streptococcus mitis, anaerobes, canned fish, canning industry, coliform bacteria, heat treatment, microbial load, molds (fungi), raw materials, spore-forming bacteria, Italy
The results of a study on the microbiological stability of canned tuna produced by Italian companies and similar canned products manufactured in countries outside Europe are reported herein. The study involved 38 samples of canned tuna of various brands, of which 14 were produced by companies outside Europe and 24 by Italian companies. Qualitative and quantitative microbiological tests were conducted for the following parameters: bacterial colony counts at 30°C, total coliforms, total Enterobacteriaceae, sulphite-reducing anaerobes, Salmonella spp., Bacillus cereus, Escherichia coli, Staphylococcus aureus, yeasts and molds. Bacterial loads and mold contamination were respectivelyin found in 8/14 (57%) samples from outside EU and 7/24 (29%) Italian samples. The bacterial flora was represented by Gram-positive bacteria (Staphylococcus warneri, Staphylococcus lentus, Streptococcus mitis, Enterococcus faecalis, Leuconostoc mesenteroides), Gram-negative bacteria (Sphingomonas paucimobilis, Acinetobacter iwoffii, Rhizobium radiobacter), spore-forming bacteria (Bacillus vallismortis), while the fungal species was represented by Penicillium spp., Rhizopus spp., Rhodotorula spp. and Alternaria spp. Excluding anomalies in the thermal treatment process of products and any contamination after treatment, the contaminations encountered in both cases were most likely due to insufficient production quality standards and the quality of the raw material used. These results may require a redefinition of the concept of commercial stability as hitherto stated.