<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Cheeses as ready-to-eat food should be considered as a potential source of foodborne pathogens, primarily <italic>Listeria monocytogenes.</italic> The aim of present study was to determine the microbiological quality of soft, semi-hard and hard cheeses during the shelf-life, with particular reference to <italic>L. monocytogenes.</italic> Five types of cheeses were sampled at different time-points during the cold storage and analyzed for presence of <italic>Salmonella</italic> and <italic>L. monocytogenes,</italic> as well as lactic acid bacteria, <italic>Escherichia coli,</italic> coagulase-positive staphylococci, yeasts, molds, sulfite-reducing clostridia and <italic>L. monocytogenes</italic> counts. Water activity, pH and NaCl content were monitored in order to evaluate the possibility of <italic>L. monocytogenes</italic> growth. Challenge test for <italic>L. monocytogenes</italic> was performed in soft whey cheese, to determine the growth potential of pathogen during the shelf-life of product. All analyzed cheeses were compliant with microbiological criteria during the shelf-life. In soft cheeses, lactic acid bacteria increased in the course of the shelf-life period (1.2-2.6 log increase), while in semi-hard and hard cheeses it decreased (1.6 and 5.2 log decrease, respectively). Soft cheeses support the growth of <italic>L. monocytogenes</italic> according to determined pH values (5.8-6.5), water activity (0.99-0.94), and NaCl content (0.3-1.2%). Challenge test showed that <italic>L. monocytogenes</italic> growth potential in selected soft cheese was 0.43 log<sub>10</sub> cfu/g during 8 days at 4°C. Water activity in semi-hard and hard cheeses was a limiting factor for <italic>Listeria</italic> growth during the shelf-life. Soft, semi-hard and hard cheeses were microbiologically stable during their defined shelf-life. Good manufacturing and hygienic practices must be strictly followed in the production of soft cheeses as <italic>Listeria-</italic>supporting food and be focused on preventing (re)contamination.</p></abstract>

Cheeses as ready-to-eat food should be considered as a potential source of foodborne pathogens, primarily Listeria monocytogenes. The aim of present study was to determine the microbiological quality of soft, semi-hard and hard cheeses during the shelf-life, with particular reference to L. monocytogenes. Five types of cheeses were sampled at different time-points during the cold storage and analyzed for presence of Salmonella and L. monocytogenes, as well as lactic acid bacteria, Escherichia coli, coagulase-positive staphylococci, yeasts, molds, sulfite-reducing clostridia and L. monocytogenes counts. Water activity, pH and NaCl content were monitored in order to evaluate the possibility of L. monocytogenes growth. Challenge test for L. monocytogenes was performed in soft whey cheese, to determine the growth potential of pathogen during the shelf-life of product. All analyzed cheeses were compliant with microbiological criteria during the shelf-life. In soft cheeses, lactic acid bacteria increased in the course of the shelf-life period (1.2-2.6 log increase), while in semi-hard and hard cheeses it decreased (1.6 and 5.2 log decrease, respectively). Soft cheeses support the growth of L. monocytogenes according to determined pH values (5.8-6.5), water activity (0.99-0.94), and NaCl content (0.3-1.2%). Challenge test showed that L. monocytogenes growth potential in selected soft cheese was 0.43 log10 cfu/g during 8 days at 4°C. Water activity in semi-hard and hard cheeses was a limiting factor for Listeria growth during the shelf-life. Soft, semi-hard and hard cheeses were microbiologically stable during their defined shelf-life. Good manufacturing and hygienic practices must be strictly followed in the production of soft cheeses as Listeria-supporting food and be focused on preventing (re)contamination.

Microbiological Quality of Soft, Semi-Hard and Hard Cheeses During the Shelf-Life

PUĐA D.O.O., Economic Zone Čaporice 133, 21240 Čaporice,

Department of Hygiene, Technology and Food Safety, Faculty of Veterinary Medicine

Macedonian Veterinary Review

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Cheeses as ready-to-eat food should be considered as a potential source of foodborne pathogens, primarily Listeria monocytogenes. The aim of present study was...

Microbiological Quality of Soft, Semi-Hard and Hard Cheeses During the Shelf-Life

Published Online: Mar 15, 2016

Page range: 59 - 64

Received: Jul 01, 2015

Accepted: Nov 19, 2015

DOI: https://doi.org/10.1515/macvetrev-2015-0068

Keywords
cheese, shelf-life,

© 2015 Josip Vrdoljak et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Microbiological Quality of Soft, Semi-Hard and Hard Cheeses During the Shelf-Life

Published Online: Mar 15, 2016

Page range: 59 - 64

Received: Jul 01, 2015

Accepted: Nov 19, 2015

DOI: https://doi.org/10.1515/macvetrev-2015-0068

Keywordscheese, shelf-life,

© 2015 Josip Vrdoljak et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
cheese, shelf-life,