"Much of the fat in processed foods is eaten in the form of emulsions such as soups, yogurt, ice cream and mayonnaise," said the IFR's Dr Peter Wilde who led the work, funded by the Biotechnology and Biological Research Council. "We are unpicking the mechanisms of digestion used to break fats down so we can design them in a rational way so that they are digested more slowly."
If the digestion of fat is delayed and fatty acids are able to reach the ileum, the final section of the small intestine, their presence stimulates satiety-inducing hormones.
IFR has been using protein layers to stabilise emulsions and delay fat digestion. It found that a whey protein that is normally stable is partially broken down when attached to the surface of an emulsion. When a surfactant is introduced, this acts synergistically with the fat, breaking down the protein layer even more effectively. With the barrier weakened, access is improved for the enzymes and bile salts that break down fat.
"We are now experimenting with heat and enzyme treatments to reduce the synergistic effect and make the protein barrier stronger," said Wilde.