People are often reluctant to have low-fat foods, as removing the fat changes the desirable taste, texture and aroma of the original product. But now, a team of researchers at the University of Massachusetts Amherst are developing a new technology that could lead to low-calorie foods that taste like the real thing.
The researchers have found that surrounding fats with layers of dietary fibre prevents the fat from being digested, which could lead to low-calorie foods with all the appeal of the real one.
Julian McClements, UMass Amherst professor of food science, said that their aim is to keep the fat in the food, but stop it from being digested by surrounding it with layers of dietary fibre.
"Foods produced with these encapsulated fats should have the same qualities as conventional high-fat foods," said McClements.
The team created the encapsulated fats by mixing oil, water and a surfactant in a process similar to making salad dressing, thus forming small oil droplets.
The surfactant coats the droplets and keeps them separate from the water until fibre is added to the mix in the final step.
Controlling the electrical charges of the surfactant and the fibre molecules allows the oil to attract the fibre like a magnet. Droplets are usually coated with two to three layers of fibre, and other substances such as proteins can be incorporated to hold the fibre layers together or to provide additional benefits.
According to the researchers, the process is suitable for encapsulating a wide range of fats and oils, ranging from orange oil to olive oil, and uses fibre obtained from apples, oranges, seaweed or shellfish.
Encapsulated fats can be used in emulsion-based foods such as beverages, sauces, desserts, yoghurt and salad dressings.
However, the team is currently experimenting with ways to chemically link the fibre layers to enhance their ability to stay intact around the fat droplets.