In addition to being an innovative technology that preserves the quality of food products, cryogenic food refrigeration also enhances efficiency and versatility in the production of frozen and processed foods. As the food industry continues to evolve, cryogenics will play an increasingly important role in meeting consumer demands. At the same time, it will promote the expansion of food product offerings.
Join us to explore in detail this technology that is transforming the way we preserve and enjoy our food.
What Is Cryogenic Food Refrigeration?
Cryogenic food refrigeration, also known as food cryogenics, is a cold application process that goes beyond traditional freezing. Essentially, this method involves using extremely low temperatures to freeze food quickly and efficiently. But what is the advantage of this ultra-rapid freezing compared to conventional freezing?
To understand it, it is essential to consider the structure of food. Food contains a significant amount of water, primarily within cells. When food is frozen slowly, as in conventional refrigeration, the water inside cells has time to form large ice crystals. This can have a detrimental effect on the texture and taste of the food when it is thawed, as large crystals can damage cell structures.
In contrast, cryogenic refrigeration aims to avoid this problem. Freezing food at extremely high speeds, it prevents the water inside cells from forming large crystals. Instead, small ice crystals are created, preserving cell integrity and, ultimately, product quality.
Prevents Water Loss
Certainly, another significant benefit of cryogenics is that it prevents water loss during the freezing process. In conventional freezing, some water evaporates, which is known as “water loss.” This loss can affect the texture and taste of food, especially when dealing with hot foods. Cryogenic refrigeration, by freezing food so quickly and efficiently, minimizes this water loss, meaning that products retain their juiciness and quality even after thawing.
Moreover, cryogenics is also used in the food industry to maintain the cold chain of fresh and refrigerated products during storage and transportation. This ensures that food reaches consumers in the best possible condition, maintaining its freshness and flavor.
What Factors Influence the Quality of Frozen Foods?
Now that we understand the importance of freezing speed, it is essential to explore the key factors that influence the quality of frozen foods.
- Cooling Speed: Cooling time is closely related to treatment temperature and cold transfer speed. This speed influences the formation, size, and location of ice crystals. The formation of crystals mainly in extracellular spaces and cell dehydration directly affects food texture. In contrast, cryogenic food refrigeration, being rapid, minimizes these problems and preserves quality.
- Dehydration: During the freezing process, foods can undergo dehydration due to exposure to cold. Cryogenics helps reduce this water loss, maintaining the juiciness of foods and preserving their quality.
- Final Temperature: Undoubtedly, storage temperature is a critical factor for the long-term quality of frozen foods. Lower temperatures, as used in cryogenic refrigeration, halt the development of microorganisms and biochemical reactions. This extends the shelf life of food.
Which Gases Are Used in Cryogenic Food Refrigeration?
Certainly, one of the fundamental aspects of cryogenic food refrigeration is the choice of gases used in this process. These gases, known as “food gases,” play a critical role in preserving the quality of food products. The quality of these gases should be ensured through certifications such as HACCP, which covers production, storage, and distribution. Similarly, it should be endorsed by ISO 22000:2005 and FSSC 22000:2017 certifications.
The two most common food gases used in cryogenic refrigeration are liquid nitrogen and liquid carbon dioxide.
- Nitrogen is an inert gas that makes up approximately 78% of the Earth’s atmosphere. For use in cryogenic refrigeration, pure nitrogen is obtained and liquefied through air filtration processes involving compression and release. This liquid nitrogen, which is at extremely low temperatures of around -196°C, is essential for food cryogenics.
- Carbon dioxide (CO2) is also present in the atmosphere but at much lower concentrations than nitrogen. Therefore, it is preferable to use concentrated sources of CO2, which require less energy. Furthermore, it is possible to effectively recover CO2 from industries with high emission rates, allowing for reuse through recycling. Like nitrogen, CO2 is purified and liquefied through filtration and compression-release processes.
How Do These Gases Transfer Energy?
Cryogenic refrigeration is based on the ability of cryogenic gases to transfer refrigerating energy to food. Depending on the gas used, different modes of energy transfer can be applied:
- Nitrogen: Liquid nitrogen is used in liquid/solid contact, either by spraying or immersing the food in the cryogenic liquid at -196°C. Once nitrogen turns into a gaseous state, which always remains at the same temperature, it continues to provide cold to the food. With the support of fans, the transfer of this cold by convection is feasible, ensuring even distribution of cold throughout the product.
- CO2: On the other hand, CO2 transfers its refrigerating energy mainly through solid/solid contact with the food. This is achieved by releasing pressurized liquid CO2 into an atmospheric pressure device, such as a cabinet or cryogenic tunnel. CO2 changes its state and forms dry ice, which can be compressed and converted into bars or dry ice pellets. When this dry ice comes into direct contact with the food, it transfers its cold and becomes gas. Similarly to nitrogen, the use of fans allows for the recovery of refrigeration left in the cold gas and ensures even distribution of cold in the products.
What Equipment Is Necessary for Cryogenic Food Refrigeration?
Logically, cryogenic food refrigeration requires a variety of specialized equipment to successfully carry out the cooling and freezing process. The main equipment includes:
- Cryogenic Tunnels: These tunnels can be easily integrated into existing food production lines. They consist of moving conveyor belts loaded with food for cooling or freezing. Fans are used to project nitrogen or CO2 and distribute cold uniformly throughout the process.
- Cryogenic Cabinets: Cryogenic food cabinets are structures that contain trays with food. This equipment allows for the treatment of a wide variety of foods through a rapid cooling process.
- IQF (Individual Quick Freezing): IQF equipment is an evolution in cryogenic food refrigeration. Astonishingly, they are designed to prepare and cool dishes like stir-fries or sauced dishes in the same machine. This provides greater flexibility in the production of frozen foods and precooked dishes.
In Which Sectors Is Cryogenic Food Refrigeration Useful and Applicable?
Cryogenic food refrigeration has applications in a wide range of sectors within the food industry. This technology is used to maintain temperature, cool, superficially freeze, or refrigerate various types of foods, including fruits, vegetables, meat, fish, and more. In general, any food product that undergoes freezing can benefit from the application of cryogenic cold to improve its quality.
Furthermore, in addition to preserving the quality of food, cryogenic food refrigeration allows industries to expand their production and diversify their offerings. This means it is possible to quickly create more complex food products, such as IQF-coated precooked dishes or multi-layered products and snacks.
Interested in Cryogenic Food Refrigeration Systems?
Since 1995, at Intersam, we design and develop refrigeration and air conditioning systems for industry and commerce. In fact, we have consolidated and recognized experience both within and outside Spain in the manufacturing of large-capacity condensers and adiabatic air coolers.
But we are also capable of designing and installing cryogenic food refrigeration tunnels tailored to your company’s needs. Whether you are in the meat, fish, seafood, fruit, or vegetable processing industry, we have the solution to preserve fresh products with their organoleptic properties intact.