Unlike mechanical refrigeration, cryogenic chilling uses a low-pressure, nitrogen-based system to cool or freeze food. This method of chilling uses gases like carbon dioxide, nitrogen, or mixtures of these two gases. Cryogenic chilling has many advantages over mechanical chilling, such as low noise, less moving parts, and the ability to retrofit existing mixers. For those who are skeptical about its advantages, read on to discover more.
When using cryogenic liquids to chill food, it is essential to keep in mind that they can be dangerous to people who are in the vicinity of the equipment. While cryogenic liquids are not toxic, they do displace breathable oxygen in enclosed spaces and can cause breakage of metals, plastics, rubber, and steel tools. In addition, cryogenic liquids turn to gas, which is easily displaced in an enclosed space, reducing oxygen levels.
Another way to minimize noise when using cryogenic liquids to chill food is to use a phase separator. This device removes vapor from the cryogen while maintaining a steady pressure within the vessel. Often, it is situated above the point where the liquid is delivered. This method of cooling allows the low-noise liquid to be delivered over short distances while preserving the quality of the product.
The use of cryogenic liquids in the food industry helps to reduce concerns about bacteria, mold and other harmful elements in food products. Cryogenic liquids help to prevent the growth of spoilage-causing microorganisms by depriving them of water they need for metabolism. Tunnel freezers can rapidly chill food products without disrupting production. Cryogenic liquids can also be used to chill raw materials.
High-efficiency cryogenic chilling processes can boost productivity and streamline food processing operations by maintaining the right food temperature throughout the facility. These are critical aspects of food safety and food quality preservation. By attending this webinar, you will gain a deeper understanding of cryogenic solutions for commercial food processing operations. During the webinar, you will hear from Erik Fihlman, Applications Specialist Manager at Linde LLC, who leads the commercialization of new solutions and marketing programs.
Another type of cryogenic cooling medium is carbon dioxide snow. Carbon dioxide (CO2), also known as dry ice, is a safe and efficient cooling medium. At -79 degrees Celsius, liquid carbon dioxide (CO2) freezes and turns into solid carbon dioxide snow. The solid phase of CO2 is also useful for cooling products in cartons, mixers and containers. It reduces the product’s temperature from 90degC to 4degC in a matter of seconds.
Cryogenic chilling is an important process in food manufacturing, particularly when the product requires a high degree of cold storage. Standard freezers typically freeze food at -18 degrees Celsius, and when the process isn’t regulated, the product can become distorted, losing its shape and quality. Many types of food are frozen using cryogenic methods, including seafood and meat. In addition to these benefits, cryogenic chilling can improve safety and production rates for producers, as well as enhance product quality and throughput.
This technique can also be used for modified atmosphere packaging, as it doesn’t use any chemicals. Instead of ammonia-based refrigerants, cryogenic liquids use nitrogen and carbon dioxide. They’re cheaper than mechanical chilling systems, and can even be retrofitted onto existing mixers. In addition to their energy efficiency, cryogenic chilling systems use inert gases.
Reduces growth of microorganisms
The process of freezing foods slows down biochemical and physiochemical reactions, reducing the activity of water and inhibiting the growth of pathogenic microorganisms. By diminishing water activity, cryogenic liquids can reduce the number of ice crystals, thus preventing growth. Rapid freezing reduces the size of ice crystals, resulting in a more stable product. The process of freezing involves a simultaneous phase transition and alteration of thermal properties.
One of the earliest methods of food preservation, drying removes water from food by evaporation. This process reduces moisture content, a prerequisite for microorganisms to activate spoilage mechanisms. Water activity below 0.9 (the minimum activity for bacteria) or 0.88 (the equilibrium relative humidity of the same temperature) is inactive for most microorganisms.