Meat species substitution: When what you see is not what you get

Food fraud is big business. Although the true extent is uncertain, such practices are calculated to cost the global food industry up to 25 billion (over ZAR 300 billion) per year and the UK Food Standards Agency (FSA) estimates that up to 10% of commercial food products may be counterfeit.1-2 In this time of rapid globalisation, when a single processed food product may contain ingredients sourced from a dozen different nations, numerous opportunities exist for unscrupulous food producers to fraudulently substitute or add ingredients which are cheaper, but not necessarily desirable.

What is the risk of meat species substitution, why and how does it occur, and what can be done to ensure the authenticity of the meat products you supply? This newsletter seeks to shed some light on these topics.

What we have found? In 2011, one of the FACTS food scientists, Donna Cawthorn, published a set of results from her PhD study conducted at the University of Stellenbosch, in which DNA testing was used to reveal that 9% of fish samples collected from seafood wholesalers in South Africa and a startling 31% of those collected from retail outlets were mislabelled with regards to species.3 In addition, simultaneous research commissioned by FACTS on various meat samples in this country has demonstrated that this type of fraud and species substitution is by no means limited to fish. A further significant concern revealed through our testing is the potential for meat products to be contaminated with undeclared species during processing. Cross-contamination can arise when poorly cleaned equipment or utensils are used for processing meat from two or more different meat species.

Whether deliberate or unintentional, the effects of meat product misdescription are similar, and include consumer deception, potential health risks and the inability of individuals to choose products for the sake of religious and ethical beliefs.

Why and how is fraud perpetuated? Due to their high prices, food products such as meat and fish are highly prone to substitution or adulteration, and such practices are often relatively simple to get away with. The flesh of many meat species differs only subtly in appearance and texture, making it difficult to identify the species based on visual inspection. Once meat is comminuted and incorporated into value-added products, however, identification based on appearance and other sensory parameters becomes virtually impossible. At another level, substitution of meat ingredients may involve the use of cheaper ingredients from the same declared species, but from different body parts (typically offal, connective tissue or blood), or the substitutes may be non-meat ingredients (e.g. plant or dairy sources).4 Apart from the concerns that meat substitution or adulteration generate from economical, religious or ethical viewpoints, counterfeit components may be toxic (e.g. melamine) and the undeclared addition of some ingredients (e.g. soy, wheat, dairy) can pose health risks for consumers with food allergies /intolerances.

The Orion meat saga The deliberate substitution of meat products was recently brought to the forefront in one of the biggest food-related scandals to hit the media in recent years. In November 2011, numerous news reports emerged indicating that Orion Cold Storage in Cape Town had been importing various products from different parts of the world and that the company was deliberately relabelling these as food-grade and Halaal.5-10 According to these reports, Orion was accused of, amongst others, importing pork products from Belgium and Ireland and relabelling them as Halaal sheep or beef products; importing kangaroo from Australia and water buffalo from India and selling these as beef products (often Halaal); importing non-Halaal poultry from Spain (via the UK) and relabelling the goods as Halaal; and importing non-food-grade milk powder for animal feed and relabelling it as Halaal skim milk powder fit for human consumption. These findings not only caused outrage among the Muslim community, but also sent waves of panic through the entire food industry.

Ensuring meat authenticity While knowing your meat suppliers and auditing them regularly may be an obvious step in protecting the authenticity of meat products, in many cases food fraud cannot be discovered by following a paper trail and detection requires “state of the art” scientific analysis.1 Today, DNA-based techniques are considered the most appropriate methods for making species identifications as identical copies of DNA are present in almost all tissue types of an individual, DNA is relatively stable at high temperatures and since the diversity afforded by the genetic code allows differentiation of even very closely-related species.11-13

Over the past few years, FACTS has developed a large number of DNA-based methods for the identification of meat species, both in single ingredient commodities (using DNA sequencing) and in complex food matrices (using species-specific detection methods) (see our full list of services below). The detection of the complete substitution of a single meat species with another is one of the more simple scenarios for identifying food fraud.

In general, DNA sequencing conducted on a queried sample will produce a DNA sequence or “fingerprint” which can be compared to a set of known reference sequences deposited in a credible genetic database. The identity of the specimen can thereby be established, which is either the same or different to the one expected. Investigating the partial substitution or adulteration of meat is considerably more difficult, since it is normally necessary to know the possible identity of the adulterant before it can be detected. To help alleviate the aforementioned difficulties, FACTS is very excited to have recently optimised an animal species screening method which allows the detection of 14 different animal species in a single reaction (more details below). This method, which relies on the use of species-specific DNA probes to detect certain target DNA sequences, will significantly reduce the costs and labour required to ensure product authenticity.

Food fraud is indeed a food industry issue. Consumers are highly reliant on the accurate and complete declaration of food constituents to enable them to make product choices that are consistent with their lifestyles. Brand loyalty can be severely compromised should this be found not to be the case. As such, DNA testing can be of great value for the routine monitoring of meat product authenticity and should be conducted whenever a case of meat adulteration or contamination is suspected.

Source: F.A.C.T.S.