The incident is still under investigation by the Food Standards Agency (FSA), which has yet to fully rule out the possibility of contamination at any stage of the production process.
Experts have agreed that the incident remained “a complete mystery” and confirmed that contamination could have occurred anywhere within the supply chain.
While declining to comment specifically on the Premier case, Dr Peter Waring, principal food safety advisor at Leatherhead Food Research told FoodManufacture.co.uk: “Typical causes of clostridium botulinum food poisoning in the past have occurred because of various reasons.
“One example included contamination at post-process level when a tin of canned salmon received a correct process but was thought to be contaminated via operators’ protective aprons from the fish-gutting being dried on the warm cans.”
Waring also said that, in the past, clostridium botulinum cases have occurred during processing and as a result of poor formulation of the product.
One expert, who did not want to be named, told FoodManufacture.co.uk: “What has clearly happened is clostridium botulinum has found its way into the sauce and the family has unfortunately consumed it. The question is: how and when did it get in there?”
“The fact that it is only one jar that was contaminated makes it very difficult to pin-point where it may have occurred.”
Clostridium botulinum – which when eaten can cause botulism - is an anaerobic bacterium that cannot grow in the presence of oxygen, according to experts.
Scientists also said that since clostridium botulinum does not grow below 12˚C, the product must have been kept at room temperature at the time of contamination.
“These sauces are shelf-stable and do not necessarily need to be refrigerated so it could have occurred anywhere from production, transport of the product through to retail,” said one expert.
“As it is only one jar that was contaminated it is very difficult to tell though, and to speculate would be unhelpful to the investigation.”
An FSA spokesman told FoodManufacture.co.uk: “Investigations into the recent botulism incident are still on-going. No stages of the production process have been given the all clear and no conclusions have been made about the source or cause of the contamination.”
Troubled Premier Foods was rocked by the incident that occurred last month, when it was revealed two children from the same family had been taken to hospital in Northern Scotland with suspected botulism.
The siblings had both eaten from a jar of Loyd Grossman Korma sauce, which is made my Premier.
As a result, the firm ordered a recall of a batch of 350g of the product with a best-before date of February 13 on November 13.
Later that week, a third child from the family was also taken to hospital with suspected botulism, although they have now all returned home.
Following on from this, the FSA revealed that Premier’s factory in Bury St Edmunds, where the sauce was produced, had shown no sign of contamination. This lead to claims from Peter Schnabl, Grossman’s agent, that both Premier and the TV chef were not to blame for the incident.
Premier was quick to distance itself from the comments however, with the FSA also labelling Schabl’s comments “premature”.
Premier said that it did not want to comment further on the incident and confirmed it was assisting the FSA with the continuing investigation.