Energy production contributes significantly to the increase in air emissions, so any reasonable economy in this area is very important. The Agricultural Research Service of the United States Department of Agriculture (ARS) and scientists from the University of California at Berkeley propose for this purpose to switch from the current technology of isobaric freezing of vegetables and fruits to isochoric, that is, to freeze in liquid.
This method has already been successfully used in medicine, and now it is possible to use it in the food industry.
The inventor of isochoric freezing is Boris Rubinsky, who described its basic principles in 2005. The idea is not to turn the water in soft organic tissues into hard ice during the cooling process, because its crystals damage their structure. To prevent this, a thick-walled chamber with a liquid inside is created, which serves as a kind of insulation, and allows you to maintain a temperature of about 0 ℃, preventing the donor organs inside the liquid from turning into ice.
Recent experiments with potatoes, fresh tomatoes and herbs have shown that isochoric freezing preserves food in a similar way. The steel in the container can be replaced with plastic. With this type of freezing, it is not necessary to ensure that the product is frozen completely, or that it freezes as quickly as possible, and therefore there is no excess energy consumption. In fact, only the container itself needs to be cooled.
Unlike conventional freezing, in which fruits and vegetables are exposed to air and freeze to a solid state at temperatures below zero degrees Celsius, isochoric freezing preserves food without turning it into solid ice. As long as food is immersed in water, it is protected from ice crystallization and the structure of the fruit is not disturbed.
Any household refrigerator can be adapted for this type of freezing by simply placing special chambers in the freezer. Redesigning industrial refrigerators and adapting the entire food industry will not be difficult, this is an undertaking with minimal costs. However, on a global scale, this will save 6,5 billion kilowatt-hours per year, which will result in a 4,6 billion kg reduction in carbon emissions.
Isochoric freezing also allows for better storage of fresh produce such as tomatoes, cherries and potatoes. Another advantage of isochoric freezing is that it kills germs during processing.
The entire chain of frozen food production and distribution can use isochoric freezing - from producers to processors, wholesalers and retailers.