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As reported on RASFF's portal, in the first 9months of 2016, a total of 13 "alerts/information for attention" were issued concerning the presence of Listeria monocytogenes in mould cheeses throughout Europe. This study analyzes the behaviour of L. monocytogenes in Gorgonzola cheese, a typical Italian soft blue-veined cheese, when contaminated at different time points. In the first challenge test, the pasteurized milk was contaminated and the complete cheese manufacture (cheesemaking, ripening) and shelf life was simulated. After a decrease during the first days of the cheesemaking, the pH remained constant for 35days (5weeks) and then it increased rapidly reaching the final values of 6.8±0.02 in the core and 5.8±0.4 on the rind. At the same time, the pathogen concentration decreased (about 2logCFU/g), although during the last week a rapid pathogen growth was observed after the rise in pH values. When the cheese was stored at thermal abuse condition (8-12°C), the pathogen concentration on the rind was 4.8±0.3 log CFU/g and after 66days (about 9weeks) no significant difference (p>0.05) was observed; whereas, a growth from 5.4±0.4 to 7.1±0.5logCFU/g was observed in the core. A second challenge test was performed using three batches of commercial slices of Gorgonzola cheese inoculated by L. monocytogenes and stored at 8°C. The maximum specific growth rates (μ max , 1/h) of L. monocytogenes estimated ranged from 0.007 to 0.061. The square root model was used to predict the μ max at others temperature and to establish the time necessary to reach the European critical legal limit of 2logCFU/g, in different storage scenarios. The predictions obtained in this study can be applied to any time-temperature profile, and in particular to the conditions to which the product is most likely to be subject in normal use, up to its final consumption. This study can be considered a valuable contribution also aimed at supporting the monitoring surveys carried out by officers of the Regional Veterinary Authority., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Water buffalo mozzarella cheese (WBMC) is a fresh stretched cheese produced from whole chilled buffalo milk. Although pasteurization of milk and the use of defined starter cultures are recommended, traditional technology involving unpasteurized milk and natural whey cultures is still employed for WBMC production in Italy. The purpose of this study was to assess the behavior of Arcobacter butzleri during WBMC production and storage under different temperature conditions (5, 10, and 20 °C). Raw milk was experimentally inoculated with one reference strain and two isolates of A. butzleri, and the count was monitored during WBMC production and storage. The bacterial count of A. butzleri decreased during curd ripening (from 7.83 log colony-forming units (CFU)/g to 4.14 log CFU/g in about 4 h) and a further decrease (>4 log CFU/g) was observed at the end of curd stretching. During storage testing, A. butzleri was never detected by direct plating, whereas it was recovered from 12 of the total 162 WBMC until the end of storage testing by enrichment. The results revealed that A. butzleri is able to survive during WBMC production and storage at different temperature conditions. Consequently, traditional WBMC produced from raw milk could represent a potential source of Arcobacter infection for humans.

Aflatoxin M1 (AFM1) is a well-known carcinogenic compound that may contaminate milk and dairy products. Thus, with the regulation 1881/2006, the European Union established a concentration limit for AFM1 in milk and insisted on the importance of defining enrichment factors (EFs) for cheese. In 2019, the Italian Ministry of Health proposed four different EFs based on cheese's moisture content on a fat-free basis (MMFB) for bovine dairy products. This study aimed to define the EFs of cheese with different MFFB. The milk used for cheesemaking was naturally contaminated with different AFM1 concentrations. Results showed that all the EF average values from this study were lower than those of the Italian Ministry of Health. Hence, the current EFs might need to be reconsidered for a better categorization of AFM1 risk in cheese. [ABSTRACT FROM AUTHOR]

Formaggio di Fossa di Sogliano is a traditional Italian Protected Designation of Origin (PDO) cheese ripened for a minimum of 5 months, with the feature of a ripening of at least 80 to at most 100 days in pits, digged into tuffaceous rocks according to medieval tradition of Italy. In this study, a challenge test using Listeria innocua as a surrogate of Listeria monocytogenes was performed, with the aim of increasing knowledge concerning the impact of the Fossa cheese process, and especially of the traditional ripening process of this PDO, on the behaviour of L. monocytogenes. Pasteurized milk was experimentally inoculated with 4.5 log CFU/mL cocktail by three L. innocua strains, and L. innocua and Mesophilic Lactic Acid Bacteria (LAB) counts as well as the evolution of temperatures, pH and aw values were monitored throughout the manufacturing and ripening processes. Throughout the ripening in maturation room a constant temperature of 8°C was observed reaching a temperature between 10 and 15.5°C during ripening into pit. In the final products data for LAB concentration, pH and aw values were roughly in accordance with literature, even if some differences were, probably due to variability of artisanal cheese productions. The numbers of L. innocua showed a slight decrease but remained stable until the end of ripening in maturation room, whereas a significant reduction of the microorganism was observed in the final product, at the end of the ripening into the pit. The findings give scientific evidence that the process of this PDO prevented the L. innocua growth, allowing us to speculate a similar behaviour of L. monocytogenes. Based on this study, the recommendation to extend as much as possible the ripening into pit (from 80 to 100 days) was provided to food business operators as a risk mitigation strategy to be implemented. [ABSTRACT FROM AUTHOR]