How to track foreign objects in food

Date: November 27, 2018

Media Release

How to track foreign objects in food

ESR food forensic scientists say they have a number of ways of working out whether an object found in food has been put there maliciously or accidentally.

ESR says while the work its food scientists do is quite variable they receive complaints about foreign materials in food on a regular basis.

There have been several cases that have hit the headlines recently of fresh produce containing foreign objects such as needles.

It’s a scenario that ESR has encountered from time to time.

ESR food forensic scientist Darren Saunders says one of the first things to look at in such cases would be if there were fingerprints or DNA on the container.

“Then there is the identification of the foreign objects themselves – if you have a thumb tack, needle or a pin you look at simple measurements, like dimensions, then compare it to what’s commercially available, analyse its composition – what sort of metal is it – where are these available and so forth,” Mr Saunders says.

Foreign objects in food are one of the big concerns ESR gets from manufacturers and suppliers, wanting to know where the responsibility lies.

“They will want to know if it is a malicious case of someone inserting, for instance, something sharp and horrible into their bread. They’ll want to know whether it was baked in.”

“We had a series of cases with needles found in baked bread and you could tell from the bag by the tiny holes in it that something had been inserted and which direction it came from – that is from the outside.”

Mr Saunders says another complaint ESR frequently gets relates to suspect rodent droppings, which, he says on the face of it, can be hard to tell from bits of burnt grease or other food ingredients.

“But under the microscope, you’ll find faecal material which contains the rodent’s hair.

“That’s because they’re always grooming and consuming their own hair, and hair can often be identified down to a species level. Mice hairs for instance are very characteristic.”

He says one complaint involving hair came from a milk company, which was continually finding ginger hairs in its on-line filter.

“We identified it as coming from a cat, so you get this image of the cat waiting until night time and jumping into the vat. Literally, the cat that got the cream!”

Listen to ESR scientist Darren Saunders explain.

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