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During the manufacture of Italian salami, a traditional meat product, a sequence of hurdles like meat fermentation, air-drying, and long ripening processes are generally sufficient to inhibit the growth of most pathogens. Furthermore, Italian salami are traditionally produced by adding synthetic nitrates/nitrites to raw meat with safety and technological aims, even if controversial opinions about their use still remain, particularly in relation to the consumer demand for natural food products. In this context, the aim of the study was to investigate the inactivation of Listeria monocytogenes and Salmonella spp. during the manufacturing process of Milano-type salami made with different formulations to evaluate the contribution of the hurdles and the vegetable or synthetic additives on the inactivation of pathogens. Thus, a challenge study was performed dividing ca. 400 kg of Milano-type salami batter into three batches: Batch (A) without nitrates/nitrites; Batch (B) with vegetable nitrates, and Batch (C) with synthetic nitrates/nitrites. The batches were separately inoculated with L. monocytogenes and Salmonella spp. and the pathogens' survival was evaluated during the fermentation, draining, and 70-day ripening of the Milano-type salami. The pathogen counts decreased in all tested conditions, even though the highest inactivation of L. monocytogenes and Salmonella spp. (p < 0.05) was observed when nitrates or nitrites were added to the batter. This study shows how the safety of these products cannot exclude the aspect of the hurdle technology during the process, which plays a major role in the reduction of pathogens, but additives like nitrates and nitrites allow for a greater margin of safety. Thus, further studies are needed to validate the use of natural compounds as alternatives to conventional preservatives in meat products. These results may provide new information to support food business operators in producing traditional foods with alternative preservatives and competent authorities in verifying the safety of the products made with natural compounds, and to control the process parameters responsible for the synergistic effect against pathogens such as L. monocytogenes and Salmonella spp. [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]

The behaviour of Listeria monocytogenes and Escherichia coli O157:H7 was studied during the manufacture and ripening of two traditional Italian Alps cheeses. Each cheese type was manufactured in a pilot plan from raw cow milk (without the addition of starter cultures) artificially inoculated with L. monocytogenes and E. coli O157:H7 to a final concentration of about 4 log CFU/mL. The pathogens were enumerated throughout the cheese making and ripening processes to study their behaviour. When the milk was inoculated with 4 Log CFU/mL, the pathogens counts increased in the first time during the manufacturing process and then remained constant, until the end of ripening, or decreased significantly. Results indicate that the environment and nature of food borne pathogens affected the concentration of the bacteria during the manufacturing and ripening process. Thus, the presence of low cells numbers of L. monocytogenes and E. coli O157:H7 in milk destined for the production of raw milk cheeses characterized by a cooking of the curd less than 48°C can constitute a hazard for the consumer. [ABSTRACT FROM AUTHOR]

This study involved ten enterprises producing Italian salami, 20 different samples of fermented sausages underwent challenge tests to assess and record the following parameters: time, temperature, pH, a w , and Salmonella counts. A linear regression model was used to describe the Salmonella spp. decay: at the end of the process the result of total Salmonella reduction was 0.97–5.84 Log 10 CFU/g and it was significantly associated with pH at the end of acidification/drying process, a w at the end of seasoning period, the duration of seasoning, and the caliber of salami respectively. High Pressure Processing (HPP) further reduced the Salmonella level by 2.41–5.84 Log 10 CFU/g with an efficacy that resulted inversely associated with a w of salami at the end of seasoning; the objective of 5-Log reduction was always reached in all the cases tested by the production process plus HPP. This model could be a useful tool for enterprises and Authorities to evaluate the efficacy of the processes to reduce Salmonella load for exportation to the U.S. [ABSTRACT FROM AUTHOR]

As reported on RASFF 's portal, in the first 9 months 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 35 days (5 weeks) 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 2 log CFU/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 66 days (about 9 weeks) no significant difference ( p > 0.05) was observed; whereas, a growth from 5.4 ± 0.4 to 7.1 ± 0.5 log CFU/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 2 log CFU/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. [ABSTRACT FROM AUTHOR]

A model describing Listeria innocua evolution according to process parameters of 51 Italian salami processes and HPP in 31 companies was developed. A total of 51 challenge tests were performed. During processing a L. innocua reduction of 0.34–4.32 Log10 CFU/g was observed and HPP further reduced the count of 0.48–3.47 Log10 CFU/g; an overall reduction of 1.04–5.68 is reached. PH after acidification/drying process, a w after seasoning, duration of the seasoning and caliber resulted associated (p < 0.05) with L. innocua decrease. HPP efficacy was associated (p < 0.05) with a w and pH of the product: higher the pH and a w after the acidification/drying and seasoning phases, higher resulted the L. innocua reduction after HPP. No significant association was observed between L. innocua and salt, nitrate and starter content and other characteristics of process. The model meets companies and Authorities needs and represents a useful tool to predict L. monocytogenes lethality, giving recommendations to food business operators interested in exportation to the U.S. [ABSTRACT FROM AUTHOR]