Scientist profile
When John Mills first embarked on a career in food safety in New Zealand, an MPI inspector didn’t mince words.
“You’ll be no use to me until you’ve seen the inside of every freezing works in the country,” he told him.
It was an exaggeration—at least, that’s what John thought at the time. But as the years passed and he found himself stepping onto factory floors up and down the country, he came to realise the truth in it. No two meat plants are exactly alike. Each has its own quirks—subtle differences in layout, equipment, and processing methods that can make all the difference when something goes wrong.
These differences are why John’s phone never seems to stay silent for long. Even on holiday, he’ll feel the familiar buzz, often met with a knowing look from his wife. On the other end of the line, more often than not, is a technical manager from a meat company looking for answers to a microbiological puzzle.
The questions vary—why is a particular batch of vacuum-packed lamb spoiling too soon? Why are swab results unexpectedly high? What’s causing an issue on the production line that no one can quite pin down?
The answers, more often than not, lie in the details—details John has spent decades learning. By his own reckoning, he’s now visited just about every meat plant in the North Island and more than a few in the South. That deep knowledge makes him one of the country’s foremost experts in meat microbiology—someone who knows not just the science, but how it plays out in the real world.
And if that means the phone keeps ringing, even on holiday? That’s just part of the job.
John, originally from the north of England, was 27 when he and his wife stepped off a plane in Auckland, ready for a new chapter in their lives. He applied for and secured a job working at Stratford Hospital in Taranaki, and at the rental car counter back in Auckland, he was handed a map and instructions about “the shortest route” to Stratford.
That route led them along State Highway 43—the Forgotten World Highway. At the time, it was the last 148 kilometres of unsealed state highway in New Zealand, winding through rugged hills, dense bush, and remote farmland.
“We thought we’d driven into Africa,” John laughs. “It certainly added to the culture shock of moving from northern England to small-town New Zealand.”
Born and raised in Burnley, north of Manchester, John had started his career as a medical laboratory microbiologist. When Stratford Hospital closed, he moved to Thames, working at the hospital lab that also tested shellfish for export to the US. The work required FDA accreditation, and he quickly realised food microbiology wasn’t just about peering into a microscope—it was about understanding systems, solving problems, and proving food was safe to eat.
That realisation became a turning point. When an opportunity arose to join the Meat Industry Research Institute of New Zealand (MIRINZ) at Ruakura, John took it.
In 1999, MIRINZ merged with AgResearch, and John found himself managing a laboratory of 28 staff dedicated to meat quality and safety research. He juggled running the lab with managing science programmes, completing a graduate diploma in business, and later earning a Master of Science.
“During my training in England, I earned a fellowship of the Institute of Medical Laboratory Sciences, now the Institute of Biomedical Sciences. That meant I could run a laboratory. But what I really enjoyed was working with stakeholders in the meat industry—gathering data, solving problems, and seeing real-world impact.”
The Science of Shelf Life
The impact of John’s work is evident in the evolution of chilled lamb shelf life.
“In 1999, the standard vacuum-packed shelf life for chilled lamb was about 63 days. Over time, we saw that increase to 70, then 77, then 84 days, with some cuts now reaching 90 days,” he says.
Advances in refrigeration, improved temperature control at loading, and tighter hygiene standards have all contributed. But behind those improvements is a scientific effort that includes plant visits, production system studies, and extensive data collection.
By testing different hygiene, packaging, and chilling protocols, researchers like John have provided the evidence to justify industry investments in blast chillers and upgraded kill-floor processes.
“A major source of contamination comes from hides, and pilot plants like the Joint Food Science Facility have been invaluable,” John explains. “We can run trials, test antimicrobial interventions, and establish the precise parameters plants need to follow.
“So, if we say a wash-down or decontamination process needs to reach 74°C for 10 seconds, we’ve worked that out in our pilot plant. MPI then takes that data and sets the industry standard.”
Industry Collaboration and Meat Safety
John’s work sits at the intersection of research, industry, and regulation.
The Food Integrity Team collaborates closely with the Meat Industry Association (MIA), MPI, and individual processing companies. Their work has influenced hygiene practices across the sector.
“We know our research makes a difference,” John says. “We see it when plants make changes after we present our findings at industry workshops. When companies act on contamination risks, they don’t always say it’s because of our research—but we know it is.”
John is a veteran in the lab and has set-up and managed a number in New Zealand during his long career in science.
One example was a plant that used a high-pressure jet on a screw auger to clean equipment—only to find it was inadvertently spreading contamination. After John’s team presented the data, the plant replaced the auger with a bottom belt, significantly improving hygiene.
Other industry-wide shifts include a major rethink on spoilage screening. When another meat company was facing unnecessary shipment rejections due to UK testing standards, John’s team demonstrated the test was irrelevant. It was soon deemed unnecessary and eventually dropped from the testing regimes preventing unnecessary losses and preserving market access.
Setting Global Standards
John’s work has also shaped international food safety standards.
In the wake of a serious outbreak of Shiga toxigenic E. coli (STEC) in the early 1990s, the USDA classified STEC as an adulterant, requiring beef producers to prove their product was free of it.
New Zealand’s research has since been critical in refining STEC testing methodologies and ensuring MPI has robust data to negotiate equivalence with overseas regulators.
John also plays a key role in regular sampling at meat plants, working alongside veterinarians and laboratory staff to maintain some of the strictest hygiene standards in the world.
“New Zealand meat plants are incredibly well managed,” he says. “We don’t have the same hygiene issues you see in some other countries. E. coli levels in NZ plants are significantly lower.
“Of course, some plants outperform others—investment cycles make a difference. When the industry is doing well, plants upgrade their systems. In tougher times, they maintain operations until conditions improve.”
Despite these variables, New Zealand’s meat processing standards remain world-class—a testament to decades of collaboration between scientists, regulators, and industry.
And if John’s phone keeps ringing with another microbiological mystery? That’s a sign his work is helping keep New Zealand’s farmers on the global stage.
