July 15 2017 by Drew Haser
On a hot summer day in July there are few treats quite as cooling and tasty as ice cream. In honor or National Ice Cream Day, which since a 1984 proclamation by President Reagan falls on the 3rd Sunday of July, let’s explore how nanotechnology has impacted one the world’s most enjoyed foods.
One of the key elements of ice cream is its creamy smoothness. Perhaps if you have ever attempted to make ice cream at home, you know that if not made correctly it can come out gritty and mealy; greatly reducing the enjoyability. The cause of gritty ice cream is the formation and aggregation of ice crystals larger than ~50um. Interestingly, this is about half the width of a human hair, and approximately the size cutoff for our tongue’s ability to detect and process texture. The traditional approach to preventing large water crystals in ice cream has simply been to reduce the amount of water and replace it with sugars and fat. Sugars and fat, besides tasting good and loading ice cream with calories, help coat ice crystals and prevent them from clumping together and growing too large.
While this approach to making delicious silky ice cream has worked for hundreds of years, there is a health consequence of consuming lots high fat, high sugar ice cream. Spurred by the pursuit to create the same rich tasting creamy ice cream but without the extreme levels of fat and sugar, scientists have sought ways to make healthier ice cream without compromising the creamy smooth texture. So how do they do it?
The secret, it turns out was waiting to be discovered in nature. Some animals, including frogs and fish, are uniquely evolved to withstand extreme cold. Normally, at frigid temperatures water in our bodies, and the bodies of animals, will start to freeze. As sharp, jagged ice crystals start to form and grow they rupture cells and damage tissue causing severe frostbite and potentially death.
However, some amphibians and fish have a mechanism to prevent the formation of large ice crystals. As previously described by the Center for Sustainable Nanotechnology, these animals create a tiny nanoparticle protein ~5 nm in size, literally called the antifreeze protein, that is able to identify, bind, and coat ice crystals, arresting their growth and preventing crystals from growing large enough to cause damage.
After isolating this natural nanoparticle, ice cream scientists are now able to substitute the tiny proteins for fats and sugar as a means of controlling ice crystals to maintaining the silky smoothness, but with significantly fewer calories.
As you enjoy your ice cream this weekend, you may opt for the traditional variety but, if you opt for the healthier alternative you may want to thank our fish friends for providing the natural nanoparticles keeping your ice cream smooth and wonderful.
p.s. What’s better than learning about the nanoparticle science of ice cream? Getting treated to free ice cream! Click here to see where you can score free ice cream for National Ice Cream Day