Food industry told not to rush horse testing
Food industry consultancy Readin Scientific Services (RSSL) has warned the food industry about the danger of rushing horse DNA tests, due to issues of accuracy.
There are two different ways of detecting horse meat in beef – the protein test and the DNA test. The ELISA method tests for protein and has a detection limit of 1-2%, but there are separate kits to test for raw and cooked meat. Due to the contamination being largely unknown, the ELISA method could possibly show inaccurate results.
With the DNA test, the detection limit is 1%, but it is possible to detect it at a lower level.
RSSL also offers two different types of DNA testing. The first involves using primer sequences (short lengths of DNA) specific to horses, which can pair with any complementary horse DNA found in the sample.
The second involves specific animal genes from within the meat sample being replicated many times, with copies being cut using restriction enzymes.
“Both of these methods work by replicating mitochondrial DNA, which is more highly conserved and more abundant in animals, than nuclear DNA. However, this also means that the methods cannot be used to quantify the amount of horse DNA found in beef. In any given sample of comminuted meat, there will be muscle meat, and potentially cells from other parts of the animal,” said RSSL.
It further stated that: “The same amount of starting DNA could arise from a small amount of muscle meat containing many thousands of mitochondria, or from a large amount of other tissue containing many thousand fewer mitochondria.”
It has therefore warned that there are “no quick answers to testing” and “no definitive way” of saying how much horse DNA is in any given sample.
- food industry
- horse dna
- detection limit
- given sample
- muscle meat
- horse dna found
- primer sequences short
- sequences short lengths
- second involves specific
- complementary horse dna