A forensic food scientist says it's a challenge trying to keep one step ahead of people who go to great lengths to illegally adulterate food.
Harry van Enckevort told the Food Safety conference in Auckland that if the 2008 melamine-contaminated milk incident wasn't bad enough, there's been another scandal in China, with more than 42 tonnes of citronella oil containing five times the permitted level of a carcinogen.
The people doing these things must have quite a high level of chemical knowledge, he says, adding: "I think people are being cleverer in thinking about what they can do to get around the system."
Mr van Enckevort says that keeping up with new technology to detect food adultation isn't cheap, with individual pieces of equipment costing up to a million dollars.
