Two inventors from Cornell University found that carbon dioxide under pressure instantly turns a creamy mass of ice – that is, creates real ice cream. The inventors say the new process can replace energy-intensive supply chain for the delivery of ice cream to stores around the world.
The idea of the researchers is that ice cream can be prepared in the end of the chain to avoid expensive costs. Five years ago, Syed Rizvi, Professor of food technology industry at Cornell and student of Michael E. Wagner has developed a system that uses carbon dioxide under pressure. What they did essentially is carbonated ice cream. Here, the effect of Joule-Thomson – when the fluid goes from high pressure to low, it can cause under certain conditions the cooling effect. That is why the freon and carbon dioxide so common in refrigeration.
On a typical plant the future of the ice cream passed through a heat exchanger. Think of it as a huge tube surrounded by smaller tubes. They are filled with chemicals like ammonia to a big pipe subjected to freezing, however the harmful substances never come in contact with food. As you move cream mixture, it instantly cools and forms ice crystals. At the end of the blades cut hardened ice cream.
In the method Rizvi does all the work carbon dioxide under pressure. Since the transition from high pressure to low pressure creates a vacuum effect, the carbon dioxide flows through a nozzle, which draws liquid mixture of the future of the ice cream. There, the compressed gas cools the ice cream to approximately minus 70 degrees Celsius. Finally, it is pushed through the nozzle in a bowl – and it all happens very quickly. Ice cream this recipe not only made faster and more environmentally friendly, but also very bad taste. Carbon dioxide has another advantage: the taste of ice cream increases from the characteristic tickling on the tongue, which is usually associated with soda.
Source — Popular Mechanics