Olive oil, milk, honey are among the most adulterated food ingredients

The seven most adulterated ingredients are olive oil, milk, honey, saffron, orange juice, coffee, and apple juice, according to a food fraud database set up by the U.S. Pharmacopeial Convention (USP).

“This database is a critical step in protecting consumers. Food fraud and economically motivated adulteration have not received the warranted attention given the potential danger they present,” said Dr. John Spink of Michigan State University, one of the researchers for the database. 

The aim of the database is to bring more focus on to the issue of food fraud.

The food-fraud was recently defined by the U.S. Department of Homeland Security as a collective term that encompasses the deliberate substitution, addition, tampering or misrepresentation of food, food ingredients or food packaging, or false or misleading statements made about a product for economic gain.

Hard to detect
The adulterants used in food fraud are often unconventional and designed to avoid detection through routine analyses. Melamine, for example, was considered neither a potential contaminant nor an adulterant in the food supply before the episodes of adulteration of pet food in 2007 and infant formula and other milk products in 2008 (with tainted products still appearing sporadically today, principally in China).

Additionally, current food protection systems are not designed to look for the nearly infinite number of potential adulterants that may show up in the food supply.

“Food ingredients and additives present a unique risk because they are used in so many food products and often do not have visual or functional properties that enable easy discrimination from other similar ingredients or adulterants throughout the supply chain,” according to the Journal of Food Science.

Glycerine, for example, is a sweet, clear, colourless liquid that is difficult to differentiate by sight or smell from other sweet, clear, colourless liquid syrups –including toxic diethylene glycol, which in the past has been substituted for glycerin with deadly consequences. Diethylene glycol has been fraudulently added to wines, and also used as an adulterant of glycerine used in pharmaceuticals.

Detection methods

In addition to identifying specific food ingredients and food categories vulnerable to adulteration, the researchers also analysed the types of analytical detection methods used to discover the fraud, as well as the type of fraud using three categories: replacement, addition or removal. The authors found 95% of records involved replacement  an authentic material replaced partially or completely by another, less expensive substitute.

An example is the partial substitution of olive oil with hazelnut oil. Other examples include potentially harmful substitution of toxic Japanese star anise for Chinese star anise (a common spice used in foods), and the partial replacement of low-quality spices with lead tetraoxide or lead chromate to imitate the colour of higher-quality spices.