Blood and offal is being illegally mixed into meat products without being declared on the label, researchers have claimed.

Tests conducted by Nottingham Trent University (NTU) in the East Midlands uncovered evidence of undeclared offal and blood in a number of meat products on sale in high street retailers.

NTU researchers tested 57 products from 10 unspecified retailers and found seven (12%) contained undeclared offal, while five (9%) contained blood serum.

According to a presentation by NTU lead scientist Professor Ellen Billett seen by The Grocer, the undeclared offal was detected at a level of 1% or more, with some products containing more than one type of offal, while the five products with undeclared blood contained serum “at a much higher level than expected.”

The discovery will lead to concerns that a new Horsegate-style mislabelling scare is on the meat industry’s hands. However, the NTU survey was small and involved new, unvalidated testing methods, and the retailers and suppliers involved have therefore not been named. It is also not clear to what extent the findings are representative at a national level.

The FSA and Defra have commissioned research to develop validated testing methods that could ultimately be used to routinely test for undeclared offal and blood. The results of this work are due to be published in late summer.

Until then, the NTU tests were simply part of “anecdotal evidence that there might be an issue”, but it was not possible to draw further conclusions, a Defra spokeswoman said.

“When businesses add offal to their food products, then they must declare it on the label to inform consumers,” said a spokeswoman for the FSA. “Local authorities will take follow-up action where undeclared offal is found, to investigate the reasons for its presence and take further enforcement action as necessary.” The tests used by NTU involved testing for proteins rather than DNA. Similar tests are also being carried out by Defra’s Food and environment Research Agency (Fera) to investigate the possible use of undeclared binding agents derived from blood in meat product lines.

Dr Adrian Charlton, one scientist involved, said Fera had been asked to prioritise cheap, budget-tier ready meals for testing and had sampled and tested 21 products from the Yorkshire region over the past year, including meat from major retailers. The results were due shortly.

Blood binders are a legitimate product that can be used to ‘glue’ together different pieces of meat, but their use must be declared. Possible illegitimate uses include binding together cheap pieces of meat to give the appearance of more expensive cuts, and for different animal species being mixed - for example, chicken pieces being glued together using pork blood binders.

“Meat and meat product authenticity is a sensitive issue particularly since the recent horsemeat scandal,” said Charlton. “I think most consumers would feel strongly if they were paying for meat which contains products from species they are not told about. For most of us meat largely means muscle tissue so adding offal or blood where this is not part of the declared recipe is something we need to know about.

“Protein-based authentication technologies provide regulators with appropriate tools to detect this kind of fraud and make sure appropriate action can be taken,” Charlton added.

Stephen Rossides, director of the British Meat Processors Association, said any suggestion a product contained an undeclared ingredient would be “a matter of concern”. But he warned the testing methods used were new, and “it’s important to have confidence in these tests.

“Despite very powerful technology,” he added, “there are some question marks over the accuracy of tests.”

A spokesman for the British Retail Consortium also pointed out work to validate the testing methodology was still under way. “The completed project will give insight into the reliability of the technique which, subject to validation, could prove a useful tool to assist businesses in identifying authenticity issues,” he added.

“As always, retailers are committed to keeping their products to the highest possible standards and will be happy to bring in new forms of testing, so long as they have come off the back of scientific evidence.”

Pete Garbutt, chief livestock adviser of the National Farmers Union, added: “After the horsemeat scandal last year, consumers want to know what is being put into the food they eat, and farmers will be concerned with any practices which serve to undermine customer trust in a product they are proud of and work hard to produce.”

Offal and blood: what the rules say

Only skeletal muscle with “naturally included or adherent tissue” is allowed to be called ‘meat’. Offal cannot count towards a product’s meat content and must be labelled separately. The generic term ‘offal’ isn’t allowed; labels must specify if it’s heart, liver etc.

Any added non-meat protein (such as blood) must be declared on the product label.

Source: Food Labelling (Amendment) (England) Regs 2003