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

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Milk and dairy products in human nutrition
Box 6.2
Melamine contamination of milk in China
Melamine is mainly used in the synthesis of melamine formaldehyde resins, which
in turn are used in the manufacture of laminates, plastics, coatings, glues and some
dishes and kitchenware. When added to food it boosts the apparent protein content
because commonly used methods for protein analysis do not distinguish between
nitrogen from protein and non-protein sources (Gossner et al., 2009). Nitrogen content
is often used to estimate protein levels in milk and hence is an agreed indicator of
the quality of milk and assurance that it has not been watered down to increase the
volume. In 2008, the Chinese government announced a recall of infant milk powder
that was contaminated with melamine (BBC News, 2010). A wide range of milk and
milk-containing products, including liquid milk, ice cream and yoghurt, was found to
be contaminated (Xiu and Klein, 2010).
The impact of the contamination was amplified because contaminated milk
products were exported from China to many countries, leading to a public health
concerns in importing countries. In addition to the serious impact on health, other
consequences included financial loss to the dairy sector, a large recall of food products
at international level, pressure on importing countries to control imports, disposal and
dumping of large quantities of contaminated milk and need for consumers to identify
alternative sources of safe milk for their families. To address this issue, immediate
actions were taken by the government and industry to improve the safety of dairy
products. However, despite this, sporadic reports of melamine in milk continue. In
February 2010 news media reported that a number of old batches of contaminated
milk powder that were not destroyed as ordered by the Chinese authorities may still
have been available for sale (Le and Hornby, 2010).
In parallel, many countries set interim tolerance levels for melamine in foods and
milk and milk products which will be re-examined as new data become available. At
the global level, the Codex Alimentarius Commission adopted global standards for
melamine: maximum levels of 2.5 mg/kg in food, 2.5 mg/kg in feed and 1 mg/kg in
powdered infant formula (2010), and a maximum level of 0.15 mg/kg in liquid infant
formula (2012) (FAO and WHO, 1995a).
More recently, melamine was added to milk in China to boost its apparent
protein content (the basis on which the price for milk was set). More than 294 000
infants became ill after consuming the contaminated milk, more than 50 000 infants
were hospitalized and six deaths were confirmed (WHO, 2008a). An increased
incidence of kidney stones and renal failure was observed in infants and babies.
6.2.3 Physical hazards
Physical hazards include a variety of materials often referred to as extraneous
materials or foreign objects (Table 6.4). A physical hazard may be defined as any
physical material not normally found in a food which may cause illness or injury to
the individuals using the product. The potential health costs of a physical hazard are