Alaska News

Avalanche research means better-tasting ice cream through science

The recent debate over "pink slime" -- the heavily processed bits of leftover meat that bolstered many a package of ground beef sold in the U.S. -- has people thinking about the science behind their food. After all, what mad genius thought to run those random scraps of beef through a centrifuge, kill the bacteria with ammonium hydroxide, and throw them in with other, less-offensive meat?

But Nestlé, the huge food company most commonly known for its candy offerings and chocolate chips, is showing the happier side of food science, with a recent study that taps into avalanche research in a quest for better ice cream. The Switzerland-based Institute for Snow and Avalanche Research, an organization that typically assists with heavier science-based matters, worked with Nestlé food scientists and other academics on the more-lighthearted study that applies practical research to figuring out why ice cream develops a skin of frost that diminishes the flavor.

Alaska is no stranger to ice cream. An oft-cited oddity of the 49th state is that despite the cold, Alaskans consume more ice cream per capita than any other state in the nation. It's not entirely clear where this factoid comes from, but there are dozens of oddball trivia websites out there that tout Alaska's counterintuitive connection to the chilly dairy treat. Maybe it's just an urban legend. It's difficult to tell, but it is known that Cold Stone Creamery gives out an award every year named for the man who brought the ice cream chain to Alaska, where it unexpectedly outperformed many stores in warmer climes.

Despite the fact that the study focuses on ice cream, it's not exactly lighthearted fare. Take, for example, the report's title: "3-D characterization of three-phase systems using X-ray tomography: tracking the microstructural evolution in ice cream." It's loaded with equations, charts and graphs, and densely academic nuggets like this:

If a structure grows homogeneously in all dimensions, a two-fold volume increase would result in a size increase by a factor of 21/3z 1.3. In contrast to this we observed an increase of the mean ice crystal size by roughly a factor of four. Therefore, the largest part of this increase has to be explained by a connection of previously unconnected ice crystals.

Whew. But the core of the study was figuring out why ice crystals form in ice cream, and what causes those ice crystals to lead to flavor loss. The scientists used X-ray tomography -- essentially sending a wave through a sample of ice cream. The result is a three-dimensional image of the ice cream's microstructure, which is so refined that scientists are able to see the tiny air bubbles in its structure. The Institute for Snow and Avalanche Research is one of the few places in the world that allows for X-ray tomography at sub-zero temperatures, which the scientists would typically use to study snow and ice characteristics.

In the end, the scientists determined that the slight temperature variations that occur during packing, transport, and storage -- including small variations in your normal household freezer -- contribute to the ongoing growth of ice crystals. As the air and the ice crystals shift within the ice cream's microstructure with even slight thawing and re-freezing, the crystals merge and morph into new, larger shapes. The larger the ice crystals, the less tasty the ice cream.

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So did scientists solve the ice cream conundrum? Not exactly, but they now have a better understanding of why the quality of ice cream deteriorates over time in what the scientists called the "coarsening" problem, caused by "the complex interplay between ice crystals and air bubbles."

Some Alaskans may never notice changes, as their ice cream only gets taken out of the freezer once. That's not enough time for the microstructure to morph before the spoon scrapes against the bottom of the container.

Contact Ben Anderson at ben(at)alaskadispatch.com

Craig Medred

Craig Medred is a former writer for the Anchorage Daily News, Alaska Dispatch and Alaska Dispatch News. He left the ADN in 2015.

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