Big freeze helps slash sat fat

A collaborative project exploring new applications for cryo crystallisation is being launched this summer after it emerged that the technique could deliver significant reductions in saturated fat in bakery products.

The technology, which has been trialled by Leatherhead Food International (LFI) using a pilot scale facility from The Linde Group, has been around for several years, said LFI microscopy project manager Dr Kathy Groves.

However, scientists had barely scratched the surface when it came to exploring its potential in the food industry, she said.

Traditionally, manufacturers have relied on ingredients such as starches and fibres to reduce fats, but novel physical techniques enabling them to produce water and air filled fat droplets, or finer emulsions with smaller droplets, have also started to attract a lot of interest, said Groves.

By melting high saturate hard bakery shortenings and then spraying them along with lower saturate oils into a stream of liquid nitrogen, cryo crystallisation produces powders containing smaller fat particles with unusual properties. These allow bakers to reduce the overall amount of shortening - and saturated fat - in the recipe. For example, using cryo-crystallised blends of fats and rapeseed oil could reduce saturated fat in short crust pastry dough from 10% to 4%, claimed Groves.

"The next step is exploring how this could be applied to other foods such as chocolate. We also want to look at how cryo crystallisation works with mixtures of fats and non-fat systems such as starches."

Other novel processing techniques with real potential included high pressure microfluidisation, which could be used to create ultra fine low-fat emulsions that more closely mimicked the texture and mouthfeel of full fat products, she said. An ultra high energy mixer housed at the University of Liverpool was also attracting strong interest from food companies keen to develop lower fat emulsions.

Finally, high energy shockwave technology designed for killing bugs (cold pasteurisation) also appeared to have potential in fat reduction given its interesting effects on the structure of emulsions, said Groves. "Firing big pulse waves through the liquids reduced the droplet size."