How science is making ice cream melt-resistant

A naturally occurring protein can create a 'bacterial raincoat' for ice cream, say Scottish researchers, making it melt-resistant and lower in fat.

Want a lower-fat, melt-resistant ice cream that can even lower your electricity bills? Researchers in Scotland may have found the answer.

A protein, known as Biofilm surface level A or BslA, found in Bacillus subtilis, is common in soil and may hold the key to better ice cream, according to an article published in the current Proceedings of the National Academies of Science.

"This is a natural protein already in the food chain," explained Prof. Cait MacPhee from University of Edinburgh, a co-author on the study, in an interview with BBC Radio. "It's already used to ferment some foods, so it's a natural product rather than being a 'Frankenstein' food."

The protein bonds with fat and air to create a moisture-resistant film, which ultimately means your ice cream could take longer to melt – resulting in a more leisurely snack and fewer sticky fingers.

Professor MacPhee said the protein is formed by microbe communities as a defense mechanism: "That protein goes to the outer surface of this community and makes a film that we dubbed a 'bacterial raincoat' – it becomes basically water repellent," she told CBS News. "That means if there are any other bugs in the environment that want to attack our friendly bacteria, they can't get through because they bounce off. It's a pretty clever strategy."

And it even makes ice cream better for you.

"By using this protein we're replacing some of the fat molecules ... but it shouldn't taste any different," Dr. MacPhee told the BBC. The development could extend to other high-fat food products as well, such as mayonnaise and chocolate mousse.

"We haven't actually tasted it yet. But what we are replacing is a small molecule that is there in a small amount," she told CBS. "There won't be any impact on the way it feels in your mouth either, because the structure is the same."

The development could also save energy. 

It reduces the amount of refrigeration needed to transport, deliver, sell, and store the ice cream, according to a press release from the University of Dundee. This could have a huge impact for manufacturers, distributors, and consumers at home.

“Freezers set five degrees lower than needed can increase energy use by as much as 20-25 percent,” according to Michael "Mr. Electricity" Bluejay. 

But don't run out to check your grocery store shelves just yet. This ice cream won’t be commercially available for at least three years, say researchers. Then, digging into a tub of BslA-enhanced Rocky Road could save you fat, calories, and energy costs.