From Boston, at a meeting of the American Association for the Advancement of Science
Ice cream that sits in the freezer too long can have a gritty taste. That’s because ice crystals grow large enough for the mouth to feel.
Now, experiments under way in Canada are using proteins extracted from winter wheat to keep ice cream’s crystals in check. The protein’s normal role is to prevent ice crystals from growing in plant tissue.
Ice cream is routinely subjected to temperature fluctuations that lead to crystal growth, says H. Douglas Goff of the University of Guelph in Ontario.
In their laboratory experiments, Goff and his colleagues add the wheat protein to solutions that serve as models for ice cream. They’ve also added the protein to batches of ice cream. Preliminary results from both the lab work and microscopy studies suggest that the protein adsorbs onto ice crystals when they are small and prevents them from growing, even after Goff exposes them to varying temperatures.
In fresh ice cream, crystals typically have diameters of 20 to 30 micrometers.
But once the ice cream sits around and the crystals grow to greater than 50 micrometers, they become detectable to eaters, says Goff. Ice cream with crystals of greater than 100 in diameter feels coarse.
Ice cream manufacturers are expressing interest in the wheat proteins, says Goff, but it will be at least a couple of years before consumers might find any in supermarket freezers.