Study of Growth Potential of Listeria Monocytogenes in Low Fat Salami: An Innovative Italian Meat Product.

In the last years, consequently to EC Regulation no. 1924/2006 on nutrition and health claims made on foods, some Italian food businnes operators (FBOs) leaders in the meat sector, invested in research to develop innovative products such as low fat salami, containing up to 30% less fat than the traditional one. For FBOs it is essential to demonstrate for each production process whether the substrate allows the growth of L. monocytogenes and whether L. monocytogenes could reach or exceed the limit of 100 cfu g-1 at the end of the shelf life, as stated by EC Regulation no. 2073/2005. In the present study, the growth potential of L. monocytogenes during the shelf life of low fat salami packed in modified atmosphere was evaluated. The results show that the product is unable to support the growth of pathogen, even if the storage temperature is between 8 and 12°C.

Growth Potential of Listeria Monocytogenes in Sliced Turkey Bresaola Packed in Modified Atmosphere.

According to EC Regulation No 2073/2005, for food business operators that produce ready-to-eat (RTE) product, it is crucial to be able to demonstrate if the product supports the growth of Listeria monocytogenes. The objective of the study was therefore to evaluate the behaviour of L. monocytogenes in sliced RTE turkey bresaola (made by cured turkey breast 4.5% NaCl, 1% sodium lactate, sodium nitrite 150 ppm and flavouring) during the shelf life of the product, simulating a contamination during the slicing operation. Considering a shelf life of 90 days, as defined by manufacturer, the packages of sliced bresaola were stored at 5°C for 7 days and at 8°C for the remaining storage time (83 days). L. monocytogenes count decreased during storage test from 1.43/1.98 log cfu/g in the three batches tested to 1.03 log cfu/g in one batch and to undetectable levels in the other two batches. The results show that the investigated product is unable to support the growth of L. monocytogenes.

Survival of Arcobacter butzleri during production and storage of artisan water buffalo mozzarella cheese.

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.

Sale of raw milk in northern Italy: food safety implications and comparison of different analytical methodologies for detection of foodborne pathogens.

The safety of raw milk sold in Northern Italy was investigated in relation to hygiene quality parameters and presence of Salmonella spp., Listeria monocytogenes, thermotolerant Campylobacter, and Verocytotoxin producing Escherichia coli O157:H7. The performance of different analytical methods used-official culture method (ISO), modified Bacteriological Analytical Manual cultural method (mBAM), and polymerase chain reaction (PCR)-was evaluated. The presence of Mycobacterium avium subsp. paratuberculosis (Map) was investigated only by PCR. All samples met regulations for alkaline phosphatase and inhibitory substance, while 18% and 44.8% of samples collected from vending machines had, respectively, somatic cell count (SCC) >300,000/mL and total bacterial count (TBC) >50,000 CFU/mL. The correlation between hygienic quality parameters in samples collected from bulk tank and vending machines showed a significant increase of TBC in vending machines meaning that raw milk was mishandled during distribution and sale. All pathogens investigated were detected in raw milk sold at vending machines; a total of five samples (5%) had at least one pathogen, of which two were detected by PCR and three by mBAM. None of the samples was positive by cultural ISO methods. Even if the comparison of analytical methods showed that none performs significantly better than the others, testing a higher volume of milk (25 versus 210 mL) affects significantly the detection rate of pathogens. Three samples (3%) were positive for Map, suggesting that raw milk is a significant source of Map exposure for consumers. The observed TBC increase and the detection of several pathogenic bacteria pose questions on the safety of raw milk; the use of ISO seems inefficient in detecting a low contamination level of pathogens in milk and consequently not appropriate as official method for testing. In order to ensure consumer's safety, a new approach for the raw milk chain is required.

Two unlinked cases of foodborne botulism in Italy at the beginning of 2010.

The study provides data on two cases of foodborne botulism caused by consumption of commercial vegetable products: artichoke preserve and cream of vegetable soup. By mouse bioassay, Clostridium botulinum toxin in both the suspected food samples was detected and identified as type B toxin. The detection of C. botulinum toxin in the artichoke preserve indicates an inadequate food production technology while the presence of C. botulinum toxin in the vegetable soup appeared to be related to wrong behavior on the part of the consumer and to faulty food preservation. The study confirms that an early identification and reporting of suspected botulism cases is vital in the prevention of accidental widespread outbreaks.