There’s a peculiar smell in the bowels of a Port Melbourne building.
“It’s just how microbiologists smell,” jokes Dean Clarke, microbiology and allergen lab manager.
James Hoang in the light-sensitive vitamins lab working on B1, B2 and B6 extractions at the National Measurement Institute.Credit: Simon Schluter
We’re in the stinkiest room of the microbiology wing at the National Measurement Institute, a government body responsible for ensuring measurements – of food, pharmaceutical goods and more – are accurate and recognised. The smell is agar, which is used by microbiologists to grow bacteria, including salmonella.
This inner-city lab led to the development of Australia’s first surgical testing of single-use facemasks during COVID. It’s also where tainted imported frozen berries were identified as the source of a hepatitis A outbreak in 2015.
“We actually had samples from victims’ freezers,” said Tim Stobaus, general manager of the institute’s analytical services branch.
Across the country, institute scientists do everything from measuring athletes’ blood and urine samples for banned substances to finding harmful chemicals in vapes and testing medicinal cannabis.
Fresh food samples are extracted and analysed for agricultural chemicals by a gas chromatograph.Credit: National Measurement Institute
The institute’s Melbourne laboratories receive, prepare, extract and then measure about 30,000 samples a year, predominantly testing food for nutritional value, allergens, safety or place of origin. This includes testing for 26 allergens ranging from peanuts to mustard, molluscs to rye and barley. Listeria and salmonella tests now take only 24 hours, down from five to six days, which speeds up the identification and containment of outbreaks.
The work here is nuanced and expensive, as scientists use machines that cost up to $550,000.
“What you see on CSI [the TV show] is a load of crap,” said Stobaus. “You can’t put a sample item into a machine and get a read-out of all the different bits in there. It just doesn’t work like that; it’s actually quite complex.”
Stobaus said Australia had robust food standards. “There are markets out there with quite stringent requirements, and we have undertaken work for export programs,” he said.
Scientist Sam Barone in the National Measurement Institute’s analytical services branch.Credit: Simon Schluter
But in Port Melbourne, we learn some hard truths about the nutritional panels on food that show how much salt, sugar and protein, for example, a manufactured food has.
“Even under the very best condition of perfect sampling, perfect preparation, perfect extraction and perfect measurement, we have a concept called measurement uncertainty, which is imprecision that’s inherent in the process,” Stobaus said. “Sometimes you’ve got to think, ‘Well, OK, that packet says it’s got 5.6 grams of fat.’ Well, probably anywhere between 5.3 and 5.9.”
For food testing to be meaningful, staff start with a representative portion of the product. This is trickier than it sounds.
“You can’t just grab an apple from a tree. You’ve got to systematically take apple samples from across your orchard,” Stobaus said. What is eaten is tested, so apples’ skins are in but apple cores and bananas’ skins are out.
Food testing at the institute.Credit: Simon Schluter
“Particularly with things like prawns or lobsters, if you just eat the flesh, that’s one exposure. But if you’re undertaking traditional Vietnamese or Chinese cooking, you use the whole thing, you can include parts of the animal that accumulate toxic substances, so it’s different depending on the use.”
In the sample preparation area, staff use nitrogen to freeze the items and grind them up for testing. “Jelly lollies are really super-hard to work with, so we’ve got a range of tools for that, such as blenders,” Stobaus said.
In the chemical testing wing, scientists weigh out a portion of a sample and add a solvent to extract things such as veterinary drug residues in meat and milk. In 2020, China suspended exports from various Australian meatworks after detecting the banned chemical chloramphenicol in beef products.
“There are very strict controls over the presence of those antibiotics in the actual meat. And this is where you can easily fall foul of the international requirements,” Stobaus said.
Traceability with food is becoming a bigger issue for consumers, and it’s particularly important for Australian-origin food, especially Indigenous food. “Being able to demonstrate that a product is what it purports to be, and is where it purports to be from, is a growing area of interest,” Stobaus said.
So, does working in food safety and nutritional testing make National Measurement Institute staff particular about what they eat?
“I eat way too many carbohydrates,” said Stobaus. “I’m conscious of highly saturated fat food and trans fat.
“But different types of food, different level of issue. So if a fish and chip [shop] has used the same oil again and again to cook their fish and chips, you’ll start to have a trans fat issue.”
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