Photopurification – which uses ultraviolet (UV) light to inactivate pathogens – could outstrip pasteurization of dairy products in the future, predicts developer SurePure.
Traditional pasteurization heats milk to make it safe to consume. Photopurification uses UV-C light to purify microbiologically sensitive liquids such as milk, wine and fruit juice.
SurePure’s technology uses radiation at a ‘germicidal wavelength’ of 254nm which inactivates pathogens, including viruses, the company claims.
Guy Kebble, CEO, SurePure, told DairyReporter.com the company has been developing the technology in South Africa over the last 10 years, and offers big energy savings as heat is not required.
“The biggest benefit is the cost of the process,” he said. “It’s simple and quick and easy to use. In the future, there won’t be any need to heat liquids to purify them.
“The dairy industry has been built on pasteurization for the last 60 years. There’s other science that needs to be looked at and taken seriously. New technologies will come, ours is not the only one, but it’s a good start. We’re all looking for energy savings.”
A commercial scale study of photopurification in the production of cheddar cheese (with raw milk) was released by SurePure this week.
The study claims the same food safety standards are reached using photopurification compared to the traditional heat treatment of cheese milk.
Unlike pasteurization, the SurePure treatment did not destroy milk enzymes that contribute to cheese texture and flavour and give natural milk its health properties, the research added.
“The adulteration of milk is quite sad,” Kebble said. “Milk is good for human beings in its raw state. And from a shelf life point of view, photopurification outstrips anything.
“UV was very much frowned upon, and it has been a hard knock on the door for us. But we’re getting past that. You look at the beauty of the technology – you don’t put anything in or take anything out.
Increased shelf life
“The technology can be used in conjunction with pasteurization, or without pasteurization. We’re also going into the UHT (ultra high temperature) equivalent and aseptic packaging – we can get the desired microbial ‘kill’ for that process. We are busy looking at that.”
In countries where pasteurization of milk is mandatory, photopurification is used in conjunction with pasteurization to increase shelf life.
Photopurification is used for milk in South Africa, and has been approved for use in India . UV treatment for fruit juices has been approved by the FDA in the US. But Kebble is frustrated by how long it is taking to get the necessary approval from the EU and US authorities to use it on milk.
“In South Africa the rules are the milk has to be labelled as unpasteurized, but that hasn’t been an issue and there’s a big fan base for it.”
“There are people who put on so much red tape. In the EU our submission went in over two years ago. The target date was February last year. That’s hugely frustrating – not only to ourselves, but the people who want to use it.”
30th March 2014
'A microbiological, biochemical and sensory characterisation of bovine milk treated by heat and ultraviolet (UK) light for manufacturing Cheddar cheese'
Authors: F Cilliers, P Gouws, T Koutchma, Y Engelbrecht, C Adriaanse, P Swart.