Detecting Misrepresentation, Adulteration in Cheese

Fraudulent practices affecting milk include dilution with water to increase the volume in conjunction with melamine to increase the apparent protein content. Although the main purpose of adulteration practices is solely economic, some cases also pose a safety risk to consumers. For example, the instance of melamine added to milk caused the death of several children in China when used in infant formula.

Premium milks from buffalo, sheep, or goat are frequently mixed with less expensive cows milk. In some countries, cows’ milk is more expensive and mixtures with goat and sheep milk have been reported.

Other typical adulteration includes the use of reconstituted milk powder instead of fresh milk, as well as the addition of detergent, urea, formaldehyde, hydrogen peroxide, salt, potato starch, and hydrolyzed leather. Some compounds are approved to use within legal limits, and beyond this point they may be consider adulterants, such as cellulose used as an additive to prevent clumping of the product, including grated cheese.

The USP Food Fraud Database carries no less than 474 entries on milk and milk products for the years 2000 to 2015, and milk adulteration is the second most frequently reported issue. This is in stark contrast to the European Rapid Alert System for Food and Feed database called RASFF. This database contains only 30 entries in the same timeframe when queried for product category “milk and milk products” and hazard category “adulteration/fraud.” None of them list the Risk Decision as “serious.” Interestingly, melamine does not even appear in the query results, even when querying the RASFF database using only the criteria “milk and milk products” under category and “serious” under Risk Decision. This is due to the fact that although the database contains 337 entries on melamine, only four notifications relate to melamine in milk, and in all cases the Risk Decision is “undecided.” This indicates that the RASFF portal does not provide a good representation of food fraud cases when only searched in the hazard category “adulteration/fraud,” a definition that should be revised by the European Authorities. It also does not correlate with the report provided to the European Parliament in 2014 on food fraud. This report lists milk and milk products, including cheese, as fourth most frequently adulterated product category.

With regards to the misrepresentation of products, Europe has created legislation to protect premium food products.

In its latest regulation EC 1151/2012, superseding the earlier regulation EC 510/2006 on quality schemes for agricultural products and foodstuffs, the European Commission clearly defines in article 12 the use of the PDO (Protected Designated Origin) label. Currently 600 products carry the PDO label, of which 186 are cheeses, 49 are from Italy.

The remainder of this article will focus on Parmigiano Reggiano cheese, one of the most popular PDOs, which was first registered in 1996. The region in which it is produced is limited to Parma, Reggio Emilia, Modena, and parts of the provinces of Mantua and Bologna, on the plains, hills, and mountains between the rivers Po and Reno. Cattle, which milk is used for the production of Parmigiano, cannot be fed silage or fermented feeds, and no additives or preservatives can be used. It was apparently Benedictine monks who started producing this cheese. Today’s production of a wheel requires 600 liters of milk. The resulting cheese wheel is left to dry and forms a natural, edible crust. The minimum maturation time is 12 months, longer than many similar cheeses.

To protect PDO products, like Parmigiano Reggiano cheese, the European Commission has bilateral agreements with some countries. There is no such agreement with the U.S., which is why one can find generic products on the market labeled Parmesan, Champagne, Camembert, etc. that do not have their origins in Europe.

Common Approaches to Detect Food Fraud

The forms of adulteration like dilution with water, skimming, or removal of fat and addition of fluid skim milk can be detected from specific gravity and fat content. Immunological technologies and polymerase chain reaction, or PCR, can be used to determine a blend of milks (e.g. cows’ milk in goat) and results are expressed as approximate content (percentage). The addition of cows’ milk can also be detected by the presence of ß-carotene, which is absent in goat milk. There are other technologies that have been or are still being used for the detection of adulteration of milk and cheese.