Friday, July 1, 2022

Sheep milk research could be a game-changer

New Zealand’s expanding sheep milk sector may soon be able to benefit from former Massey University student Jolin Morel’s PhD research, which looked at developing a new way of freezing ovine milk. Colin Williscroft reports.

New Zealand’s expanding sheep milk sector may soon be able to benefit from former Massey University student Jolin Morel’s PhD research, which looked at developing a new way of freezing ovine milk. Colin Williscroft reports.

The patent process is in motion and work is under way to build prototype on-farm units for freezing ovine milk that could take the NZ dairy sheep industry to the next level.

Jolin Morel graduated with a PhD from Massey earlier this year, his research focused on finding a better way to freeze sheep milk, something that will benefit the smaller players in NZ’s dairy sheep industry and open the way for more farmers to get involved in a sector that has been identified as one with a smaller environmental footprint than traditional dairy farms.

Morel says the genesis of his project involved a Ministry of Business, Innovation and Employment (MBIE) programme called Food Industry Enabling Technologies, which aims to create new technologies within the NZ food industry.

Having identified that the bigger players in the NZ sheep milk sector, such as Maui and Spring Sheep, had the size or economies of scale necessary to look after their own production, he looked at how he could help smaller operators and through that encourage others to get into the dairy sheep sector.

He says because ewes only produce between one and one-and-a-half litres of milk per day during peak lactation, an average size NZ dairy sheep farm will produce between 600-1000 litres of milk a day.

That’s not economical for daily tanker pick-up, so the aim of the project was to create a piece of equipment that would allow milk to be frozen on-farm, without it losing quality so farmers could hold it until they had enough milk accumulated for pick-up.

“Rather than sending 600 litres a day, every two weeks, they could send 10,000kg of frozen milk, which would simplify the logistics for them,” Morel said.

“The idea is that this unit will be able to be parked next to a shed, with milk taken from the vat over the course of the day and frozen into pallets.”

The research focused on the changes that occur during the frozen storage of ovine milk, the transitions that occur during the freezing process and the effect of freezing conditions on the ice structure in the frozen product.

From that scientific basis, a continuous freezing system was developed and tested, which is currently being commercialised in partnership with a freeze dryer manufacturer that also produces on-farm chilling equipment.

The technology is in the process of being patented.

During the course of his research, Morel discovered there were other sectors of the food industry that could also benefit.

“It turns out it’s quite useful for freezing lots of liquid products. We’ve tried it with a range of fruit-based liquid products, which has been quite successful, some other dairy products and other liquid foods,” he said.

“It’s become more than just about sheep.”

Although ovine milk has been frozen before, this new method is a step or two up, even on the international stage, which is why patents have been applied for.

“There are some people who freeze sheep milk,” he said.

“However, what they will often do is pack it into a 20-litre bladder or a 20-litre bucket, and then stack them in a blast chiller or chiller.

“When they come to be sold they have to be thawed individually, then opened, then handled from there, so there’s a lot of manual labour involved.”

He says the quality of milk frozen in that way is not as good as milk frozen using the new process, partly because of the time it takes to thaw 20-litre blocks.

“What we’ve come up with is effectively a completely novel way of freezing liquid food products,” he said. 

“There are some other ways where you can continuously freeze liquid so they look like an ice cream machine or something similar, but this method is a lot more simple, it relies on careful control of the freezing process.”

Contributing to the development of the NZ primary sector is in Morel’s DNA.

George Wickham, his grandfather on his mother’s side, was an associate professor and sheep specialist at Massey and his father, Professor Patrick Morel, specialises in animal science at Massey’s School of Agriculture and Environment.

After picking up his PhD, these days the younger Morel works for Callaghan Innovation, looking at ways to take primary industry byproducts and extract high-value products from them.

“Taking waste from apple processing – the peels and stuff, the cores – and seeing what high-value product can be made from that, rather than turning it into cow food,” he said.

As well as that, he’s keeping an eye on the commercial development of his PhD research, which could be a game-changer for the NZ dairy sheep sector.

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