23 cheeses in two reveals a smooth, glistening, plastic-like appearance of the entire cut surfaces
without a center curd core.
Several factors determine whether and at what level L. monocytogenes could become introduced to contaminate the final product. Extrinsic factors include the microflora of the incoming milk,
the possible use of a microbial control treatment, potential cross-contamination during manufacturing, and the temperature at each step. The most significant intrinsic factors are the
water activity a
w
and pH of the milk and nascent cheese as the process progresses.
Figure 1: General flow chart for commercial production of Camembert.
2.4. Overview of the Cheese Industry
The cheese-making industry in the U.S. and Canada is highly diverse, both in terms of the number and types of products produced and in the diversity of the producers. For example, the
September 2007 A.C. Nielsen database of total cheese sales lists over 16,500 Universal Product Codes UPC and several hundred brand names used by large retailers in the U.S. The Nielsen
Pasteurize whole milk ↓
Inoculate milk with starter culture mesophilic andor thermophilic culture
for stabilized cheese only thermophilic culture ↓
Add penicillium candidum to milk ↓
Ripen milk ↓
Add coagulant ↓
Cut coagulum ↓
Curd drained into hoops; hoops turned for drainage ↓
Cheese salted brine or dry salted ↓
Cheese onto racks, into ripening room – optional mold can be sprayed on
surface of cheese, cheese turned
↓ Mold will form within 2 week period
typically 7-10 days for commercial operations ↓
Cheeses are packaged in breathable parchment paper and packaged ↓
Cheese is aged and distributed
24 database contains scanner data from a set of large retailers and national merchandisers. The data
do not include products marketed directly to consumers or through small or specialty retailers. The USDA National Agricultural Statistics Service NASS estimates that over 400 million
kilograms 900 million pounds of cheese were manufactured in 2007.
There are few data available on the amount of Brie and Camembert produced yearly in the U.S. and Canada. The USDA NASS does not gather data on domestic production of these cheeses,
although USDA import reports show that approximately 12 million kg 26 million pounds of soft-ripened cheeses of all sorts are imported into the U.S. yearly. The Nielsen database contains
over 100 UPCs for Brie and over 50 UPCs for Camembert products imported and domestically produced. The sales associated with these UPCs total approximately 2 million kg 4.4 million
pounds of Brie and 0.4 million kg 0.9 million pounds of Camembert yearly through the retail outlets reported in the Nielsen data base.
Brie and Camembert production in the U.S. and Canada generally occurs in facilities that can be characterized as either large producers or as small artisanal or farmstead producers. Although
the outline of the cheese production process is the same regardless of scale, there are a number of factors that differ between the large and small producers that may have a significant impact on
the microbiological safety of the final product. These factors include, for example, the need to pool milk from multiple herds or farms and the time for and conditions experienced during
transport and storage of the milk prior to cheese-making.
Unfortunately, there are few data available in either the U.S. or Canada that characterize production volumes and distribution patterns for soft-ripened cheeses, or the specific types Brie
and Camembert, and no data on the practices used by artisanal and farmstead producers, the amount of cheese produced in this sector, conditions experienced during distribution and
handling, or the consumption habits of consumers who purchase these products. These data gaps made it impossible to accurately model the integrated public health impacts such as total
number of illnesses per year or population illness rates from L. monocytogenes in these cheeses. As an alternative, this risk assessment used baseline models and a series of scenarios to examine
