Harvard researchers were inspired by a talk given by Dr Rodney Bee, a chemist with Unilever -- the company is a major producer of ice cream, amongst other food products.

Bee showed how esing a simple kitchen mixer, he had managed to create ice cream with bubbles one micrometer in size.

"Small bubbles on that scale never last because of surface tension -- they instantly disappear." said Professor Howard Stone of Harvard's School of Engineering and Applied Sciences (SEAS).

"What Rodney showed on that screen was extraordinary,"

"I asked him how he created his foams, and he said he used an ordinary kitchen mixer."

"The next day I went out and bought a kitchen mixer for the lab."

SEAS graduate student Emilie Dressaire worked with Stone to formulate a syrupy mixture of simple sugars and water.

When the mixture was whipped, a foam was created with a crystalline structure that protected the bubbles from popping.

"The bubbles are fairly happy in it," said Dressaire.

"We were able to keep them for a year."

The bubbles could be modified for other uses, such as cosmetics or as contrast agents for ultrasound imaging.

They could even be used to replace fat molecules in food products, such as ice cream and mayonnaise.

"The lifetime is so long, which is the interesting part for industry," Dressaire said.