Enlarge / Don’t you hate it when ice crystals form and make your ice cream all crunchy? Scientists at the University of Tennessee found that plant cellulose could work better than the additives manufacturers currently use to slow the growth of ice crystals. (credit: Sally Anscombe/Getty Images)
We’ve all made the mistake of leaving a container of ice cream on the kitchen counter for a bit too long. Sure, you can refreeze the half-melted treat, but you may find that the texture is far more crunchy than delectably creamy afterward. The culprit is overly large ice crystals. Scientists at the University of Tennessee think they’ve found a plant-based additive to stop the formation of these crystals, and it’s more effective and cheaper than the additives currently used by ice cream manufacturers. The researchers presented their work at this past week’s meeting of the American Chemical Society in San Diego.
“Food science is not cooking,” Tao Wu, a food scientist specializing in carbohydrate chemistry, said during a press conference. “It’s a multi-disciplinary field that uses chemistry, biology, and engineering to solve real-world problems in the production of food. For instance, we must use good chemistry knowledge to produce high-quality ice cream.”
The basic science involved in making ice cream is well known. (Physics students have even been known to use liquid nitrogen to make their own ice cream in the lab.) Just heat milk, cream, and sugar until the sugar dissolves; cool the mixture; and add any flavorings. Then slowly churn that mixture as it freezes. This adds air to the mixture, inflating the volume (overrun). The best ice creams, including gelato, have an overrun of less than 25 percent compared to cheap commercial ice creams, where the overrun can be as high as 100 percent. That higher overrun is why cheap ice creams melt more quickly and don’t store as well. Finally, pack the soft ice cream mixture into containers for the final step in the process (hardening).
