Milk-and-Dairy-Products-in-Human-Nutrition-FAO

Chapter 6 – Safety and quality 259
Box 6.3
Raw milk and raw milk cheeses
Important safety controls for raw-milk cheeses include minimizing the number of
pathogens in the milk through hygienic production and milking conditions; removing
any remaining bacteria through technologies such as bactofugation or microfiltration,
or prevent them from growing through low pH; using long maturation time and
high salt content to lower the water activity; controlling the temperature at which
the cheeses are processed and stored; and selecting starter cultures that produce
bacteriocin.
Despite these controls, raw milk and raw-milk cheeses have been implicated in a
number of outbreaks of food-borne diseases, and there is a need for concerted action
by government and producers to ensure that controls specific to the particular product
are implemented correctly and thoroughly.
Problems can arise when raw milk is used in cheese types in which hazards are not
easily controlled during processing and with pathogens such as Mycobacterium bovis,
which can survive in mature, unpasteurized cheeses, is very resistant to chemical
disinfectants and is largely unaffected by the pH of the cheese (de la Rua-Domenech,
2006). Traditional cheese varieties made from raw milk should only be made from
milk from herds that are certified as free of brucellosis and bTB (Creamer et al., 2002).
Public-health authorities in many countries require that cheese made from raw
milk be aged for 60 days, although this practice may not be fully effective. An alternative,
risk-based approach is to require demonstration that the cheese processing can
consistently provide a level of health risk equivalent to or lower than that produced
by thermal pasteurization. Labelling and consumer education may also be required to
support informed consumer choice.
Risks and effectiveness of associated control measures also need to be assessed
in the context of the actual production environment and market chain, which differ
markedly between countries and especially between developed and developing
countries.
In developed countries, the milk supply chain is usually quite sophisticated,
organized and large scale, and use of technologies to mitigate risks, especially
refrigeration and pasteurization, is common. The milk supplied to modern cheese
factories and dairy plants is of very high quality and after pasteurization contains
only a few hundred bacteria per ml of milk (Fox and Cogan, 2004).
In contrast, in many developing countries the market is dominated by unpasteurized,
informally marketed milk produced by smallholders (De Leeuw et al., 1999;
COMESA and EAC, 2004). In general, developing countries still face very specific
challenges in maintaining the quality of the milk from milk producer to dairy plant
for processing or to the market for direct sale.
A number of challenges prevail in the more informal dairy sector in rural areas,
such as poor infrastructure and transport systems, lack of or interrupted electricity
supply, poor hygienic conditions and inadequate transport and storage. Many