Food cryogenics is the process by which foods are rapidly frozen in order to maximize their preservation. It can occur at any time between production and sale of the product. To date, there are different types of processes, useful at various stages of the journey of food to your refrigerator.
The most elaborate and effective process in food cryogenics is undoubtedly shock freezing by CO₂ (carbon dioxide) or cryogenic N₂ (nitrogen). It is a rapid cooling of food with food grade liquid CO₂ or nitrogen. Such a procedure allows the following advantages:less loss of water during defrosting, improved retention of initial freshness, longer shelf life of frozen foods compared to conventional processes, less food burns from the cold.
Next comes individual freezing (IQF) . This method is especially suitable for small, fragile or individual products. IQF (Individual Quick Freezing) individual freezing makes it possible to crust and freeze (continuously) small fragile products. Examples:raspberries, grated cheese, fruits, vegetables, meat pellets, bacon bits, diced ham...
Also read:Dry ice blasting; how effective is it?
Tunnel freezing with nitrogen (N₂) or carbon dioxide (CO₂) cryogenic liquids is an instant cooling process. Generally, this system is found in the form of freezing tunnels, placed directly in the food production lines. The cryogenic freezing involved allows the water present in the product to crystallize very quickly, resulting in reduced volume loss. This rapid cooling system also keeps the quality of the food intact.
Some products must be frozen quickly after cooking or pasteurization. In this case, continuous rapid cooling is the most suitable. It involves freezing after cooking with liquid nitrogen or dry ice, which ensures the continuity of the cold chain. Application example:frozen pizzas.
The cryogenic equipment necessary for these processes is nowadays, for the majority of techniques, simple and reliable. Some companies strive to design systems that are compact (so that they fit easily into production lines), that are easy to use, maintain and clean.
