Quantitative risk assessment of Listeria monocytogenes in traditional Minas cheeses: The cases of artisanal semi-hard and fresh soft cheeses

Author(s)

Campagnollo, Fernanda Bovo ^{[1, 2]} ; Gonzales-Barron, Ursula ^[3] ; Pilao Cadavez, Vasco Augusto ^[3] ; Sant'Ana, Anderson S. ^[1] ; Schaffner, Donald W. ^[2]

Affiliation

^[1] Univ Estadual Campinas, Fac Food Engn, Dept Food Sci, Campinas, SP - Brazil

^[2] Rutgers State Univ, Sch Environm & Biol Sci, Dept Food Sci, New Brunswick, NJ - USA

^[3] Polytech Inst Braganca, Sch Agr, CIMO Mt Res Ctr, Campus Santa Apolonia, Braganza - Portugal

• Document type: Journal article
• Source: FOOD CONTROL; v. 92, p. 370-379, OCT 2018.
• Web of Science Citations: 5

Abstract

This study estimated the risk of listeriosis from Brazilian cheese consumption using quantitative microbial risk assessment (QMRA). Risks associated to consumption of two cheese types were assessed: artisanal ripened semihard cheese (produced with raw milk) and refrigerated fresh soft cheese (produced with pasteurized milk). The semi-hard cheese model predicted Listeria monocytogenes growth or decline during ripening, while the soft cheese model predicted pathogen growth during refrigerated storage. Semi-hard cheese modeling scenarios considered L. monocytogenes starting concentration from - 2.4 to 6 log CFU/mL in raw milk and three ripening times (4, 22 and 60 days). Soft cheese modeling scenarios considered L. monocytogenes starting concentration from - 2.4 to 4 log CFU/mL in milk. The inclusion of anti-listerial lactic acid bacteria (LAB) in cheeses was also examined. Risk of listeriosis due to consumption of soft cheese was 6000 and 190 times greater than that of semi-hard cheese, for general and vulnerable populations, respectively. Aging semi-hard cheese reduced risk, and risk was influenced by L. monocytogenes starting concentration. Aging cheese with inhibitory LAB for 22 days reduced risk over 4 million-fold when L. monocytogenes was assumed to be 6 log CFU/mL in raw milk. The inclusion of inhibitory LAB also reduced risk of listeriosis due to soft cheese consumption, but not as much as for semi-hard cheese. QMRA results predicted that consumption of contaminated cheeses can carry a high risk of listeriosis, especially for vulnerable populations. Scenario analyses indicated that aging of semi-hard cheese and inclusion of antimicrobial LAB mix in semi-hard and soft cheeses are effective risk mitigation measures. (AU)

• FAPESP's process: 16/09346-5 - Modeling the inhibition of Listeria monocytogenes by lactic acid bacteria during ripening of Brazilian artisanal cheeses and the impacts of microbial interaction on cheese safety
• Grantee: Fernanda Bovo Campagnollo
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 14/14891-7 - Modelling the inhibition of Listeria monocytogenes by lactic acid bacteria (LAB) in traditional Minas cheeses
• Grantee: Fernanda Bovo Campagnollo
• Support Opportunities: Scholarships in Brazil - Post-Doctoral