UK researchers are getting closer to finding the cause of black bone syndrome, a discolouration in cooked on-the-bone chicken products.

Speaking at the recent DSM Technical Seminar near Coventry, Bob Fleming of the Roslin Institute, Edinburgh, said he first heard of the syndrome from a Canadian colleague at the University of Alberta in 2000.

But he then discovered that it had been around for some years, having been called “meat discolouration” in the USA. “Researchers over there associated it with slow chilling rates, disrupting cells and leading to blood migrating into meat.”

But the profile of the condition had increased as more consumers have been noticing it. “Consumers are sometimes not buying it [on-the-bone chicken] because of the colour.”

To see if it also occurred in the UK, he described how he bought several products from local stores and found it was present. “It consisted of the top ends of bones being blackened and it became more obvious when cooked. You get staining that then goes on to the meat.”

This prompted him to study it in detail with support from DSM. He aims to determine its prevalence, develop a standardised recording system of the syndrome and investigate a possible method of preventing it by feeding a vitamin D3 product (HyD).

It is well established that supplementing broiler diets with HyD, which is a more available form of vitamin D, to birds can boost bone health. This is significant, as Mr Fleming hypothesised that the syndrome was due to an increased porosity of fast-growing bone, which then allowed the marrow to leak into the meat.

Early results from the trial showed that it was relatively common in on-the-bone chicken from all supermarkets, particularly frozen. It was also present in samples from France.

He also found that supplementing the diet with HyD copuld help mitigate the syndrome, but it did not prevent it. The trial is ongoing.