Ex-Unilever scientist seeks to cash in on light-as-air emulsions

Scientists at the University of Birmingham, UK, are in talks with leading food manufacturers about commercialising a technology enabling them to more than halve the fat in foods such as salad dressings by using air filled emulsions.

Unilever's former chief scientist Ian Norton, now professor of soft solid microstructural engineering at the University of Birmingham, said he was "extremely excited" about the potential of hydrophobins derived from mushrooms - and other proteins with similar properties - to create air-filled emulsions that could help slash the fat content in emulsion-based foods.

Norton, who has more than 60 patents to his name covering everything from low fat spreads to shampoo, spent more than 25 years at Unilever before going back into academia last summer. "Hydrophobins have been used to stabilise foams, but using them to stabilise emulsions in this way is very new and exciting," he said.

"They are unique proteins; when you get them onto an oil or an air interface, they aggregate and you get an elastic interface.

"What we're trying to show is that if you take some of the oil droplets out of mayonnaise and you put air-filled emulsion droplets in, you can then start to build emulsion products with 50% fat removed; but you can't tell the difference, either in terms of the physics in the jar, or the sensation when you actually eat it."

The rheology of the mayonnaise would be maintained by manipulating the size and functionality of the air cells so that the mouthfeel of the full and reduced fat versions were identical, he said. "Several companies are showing a lot of interest."

Hydrophobins are low molecular weight proteins extracted from mushroom, said Norton. "However, you don't necessarily have to use mushrooms to get the same effects. We have just come up with an alternative to fungal hydrophobins using other materials."

Other potentially exciting areas of research included acid sensitive alginates that created a self-assembling structure inside people, said Norton.

"You can drink them but when they hit the acid in the stomach they gel. They effectively structure inside your stomach and slow down the way that your stomach empties. If you can delay people's eating between meals, that could have an enormous effect."

Technology like this, rather than pills, would play a key role in helping people to balance their energy intake and expenditure, he claimed.

"I don't see people taking tablets to solve their problems; you've got to get things into food."

*The full interview with professor Norton will run in the January issue of FIHN's​ sister title, Food Manufacture​ http://www.foodmanufacture.co.uk​