Low-fat foods are often disappointing to consumers since removing the fat changes the desirable taste, texture and aroma of the original product.
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.
“Our goal is to keep the fat in the food, but stop it from being digested by surrounding it with layers of dietary fiber,” says Julian McClements, UMass Amherst professor of food science. “Foods produced with these encapsulated fats should have the same qualities as conventional high-fat foods.” The research team includes McClements and UMass Amherst food science professors Eric Decker and Yeonhwa Park.
To make the encapsulated fats, small oil droplets are formed by mixing oil, water and a surfactant in a process similar to making salad dressing. The surfactant coats the droplets and keeps them separate from the water until fiber is added to the mix in the final step. Controlling the electrical charges of the surfactant and the fiber molecules allows the oil to attract the fiber like a magnet. Droplets are usually coated with two to three layers of fiber, and other substances such as proteins can be incorporated to hold the fiber layers together or to provide additional benefits.
The process is suitable for encapsulating a wide range of fats and oils, everything from orange oil to olive oil, and uses fiber obtained from apples, oranges, seaweed or shellfish. All the ingredients are food-grade, so this technology requires no FDA approval to use. Encapsulated fats can be used in emulsion-based foods such as beverages, sauces, desserts, yoghurt and salad dressings. They remain stable in acidic foods and during freezing, thawing and cooking, and can also handle large amounts of salt.