The trade body is believed to have notified the FSA (Food Standards Agency) that the salt target for mature cheddar should be increased to 2% as an immediate precautionary measure, as against the 2010 target of 1.95%.
Salt helps prevent the chemical histamine forming when the milk-based amino acid histidine is broken down, either by proteolytic micro-organisms or certain types of milk enzyme such as natural milk contaminants Escherichia, Enterobacter, Lactococcus, Lactobacillus and Leuconostonatural.
Reactions to gistamine
Histamine occurs when cheese is improperly handled during production or not stored at a cold enough temperature, where warm conditions allow bacteria to multiply and produce it.
Symptoms of a histamine reaction – which can even affect those without known allergies – include a skin rash, low blood pressure, vomiting and diarrhoea.
Although many cheese producers enforce a rigorous testing regime to monitor the chemical’s levels, one industry source told FoodManufacture.co.uk that extensive histamine testing is impractical and expensive, while questions arise about its viability, given variability in histamine levels even within a single cheese or cheeses within the same batch.
Regular testing of levels
British Cheese Board secretary Nigel White said the histamine safety issue in cheese "hadn't reared its head in a long time", with the last case he could recall around 10 years ago, although he said the industry took the risk extremely seriously.
"Histamine does build up in some products over time, and not just cheese. But in a 15-18 month old cheese levels are not predictable, since they depend upon so many factors."
"Very little is written on histamine in cheese, it's more of a concern in shellfish, I believe (although I'm no food safety expert). But if it were a really serious issue then people would sponsor more research."
White added that he knew of one paper suggesting that reduced levels of salt in a particular cheese led to higher histamine levels, but said the industry hadn't encountered any wider problems in regard to the chemical when reducing salt levels in accordance with FSA targets.
Histamine not a major issue
One mature cheese producer we contacted, who wished to remain anonymous, said problems with histamine were not a major issue for his firm: “We regularly test our cheese for histamine, and have discovered no adverse results.
"We don’t perceive it to be a huge problem and we actually use a salt content lower than the levels [1.95%-2%] you mention, and it’s never been an issue so far as we’re concerned.”
According to a FSA withdrawal notification on January 31, The Co-operative removed two own-label cheeses from sale: British Extra Mature Cheese with a best-before date of February 24 2011 and Welsh Extra Mature Cheese with a best-before date of March 14 2011.
“Eating more than small amounts of the products may cause symptoms similar to an allergic reaction…more likely to occur in sensitive individuals or children,” the FSA warned.
FoodManufacture.co.uk was unable to contact anyone at Dairy UK for comment.