The recent crisis involving Chinese milk adulterated with melamine once again brings food safety into the public spotlight. The problem has quickly become an international one, with melamine detected in U.S.-produced baby formula, as well as in chocolates distributed in Canada, biscuits marketed in the Netherlands, condensed milk manufactured in Thailand, and eggs sold in Hong Kong. Chinese dairy exports have declined more than 90% since the contamination became public.
The international community responded strongly to the crisis; the U.S. Food and Drug Administration (FDA) even took the unusual step of blocking the importation of an entire category of one country’s foods: Chinese products containing milk. The FDA has also found baby formula produced in the United States to be safe after establishing a maximum residue limit (MRL) of 1 part per million (PPM) and testing more than 70 products. The European Commission also banned the import of Chinese milk and milk products into the European Union (EU), including all products for infants and young children containing any milk of Chinese origin.
The effects of such bans on the food production industry are multiple, profound, and far-reaching. A producer that depends on a banned imported foodstuff not only suffers economic loss to the impacted product but also faces lost sales caused by loss of public confidence. The resulting brand damage can be devastating, and recovery can require significant time and expense when consumers have moved on to other suppliers’ products.
This most recent crisis underscores the need for increased food safety vigilance. Fraudulent adulteration of food products should be dealt with rigorously, with stringent penalties for offenders. Efforts to harmonize global testing methods and limits for allowable contaminant levels must also continue, while response to potential safety threats can be improved by the adoption of methods, systems, and regulations that enable the tracking of a foodstuff from farm to fork. Finally, a more selective sample preparation and testing technology is needed to enable rapid screening of food contaminants.
Food safety monitoring systems are in place worldwide to detect and prevent human exposure to food residues and contaminants. However, the melamine crisis highlights a more sinister threat to food quality and safety: fraudulent food adulteration.
Melamine was intentionally added to milk in China for one purpose only—to artificially increase the measured protein content of the milk. The Kjeldahl assay, which determines the total nitrogen in a sample, is the test most widely used to determine the total amount of protein in foods. Because every molecule of melamine contains six atoms of nitrogen, adding a small amount of melamine to milk significantly increases the amount of nitrogen detected in the test, resulting in erroneously high protein estimates. Often, the melamine used for this purpose also contains cyanuric acid, an analog that complexes with melamine to form crystals that accumulate in the kidneys, frequently leading to kidney stones and renal failure.
The Chinese melamine incident was a case of intentional, greed-induced fraud perpetrated by people with knowledge of testing methods. Intentional misrepresentation of food also occurs; recently, fish were mislabeled as more expensive varieties in New York fish markets and restaurants, a deception discovered by researchers using DNA testing. The damage inflicted by such perpetrators is incalculable, and it exacts a high cost in shaken public confidence in the global food production system. Constant international vigilance, appropriate criminal penalties, and globally coordinated efforts to enforce those penalties should be considered to assure the future safety of the food production system.
Global Methods Harmonization
The milk adulteration incident points out the need for a continued effort to generate a single, globally harmonized set of MRLs, as well as testing methods for food residues and contaminants. For example, China and the FDA have now set an allowable limit for melamine of 1 mg/kg (1 PPM) for infant baby formula and 2.5 PPM for other products, while the European Commission has set a limit of 2.5 PPM in all milk-containing products and a tolerable daily intake of melamine of 0.5 mg/kg body weight.