Two inventors at Cornell University discovered that carbon dioxide under pressure instantly turns a creamy mass into ice - that is, creates real ice cream. The inventors say the new process could replace the energy-consuming supply chain of delivering ice cream to stores around the world.
The researchers' idea is that ice cream can be made at the very end of the chain to avoid costly costs. Five years ago, Syed Rizvi, professor of food technology at Cornell and student Michael E. Wagner, developed a system that uses pressurized carbon dioxide. What they get is essentially carbonated ice cream. Here the Joule-Thomson effect works - when a liquid passes from a state of high pressure to a low one, it can provoke a cooling effect under certain conditions. This is why freon and carbon dioxide are so common in refrigeration technology.
In a typical plant, future ice cream is passed through a heat exchanger. It can be thought of as a huge pipe surrounded by smaller pipes. They are filled with chemicals like ammonia to freeze a large pipe, but the harmful substances never come into contact with food. As the creamy mixture advances, it instantly cools and forms ice crystals. At the end of the blade, the hardened ice cream is cut away.
In the Rizvi method, carbon dioxide under pressure does all the work. Since the transition from high pressure to low pressure creates a vacuum effect, carbon dioxide passes through a nozzle that draws in the liquid mixture of the future ice cream. There, compressed gas cools the ice cream to about minus 70 degrees Celsius. Finally, it is pushed through the nozzle into the bowl - and it all happens very quickly. Ice cream according to this recipe is not only made faster and more environmentally friendly, but also tastes very good. Carbon dioxide has another benefit: the taste of ice cream is enhanced by that characteristic tickling tongue that is usually associated with soda.