When it comes to preserving and prolonging the life of commodities, freezing is a key method utilized by the food industry. O.S Gautam delves into the various conventional and commercial freezing methods employed by the food industry in order to achieve this goal.
Microflora, inbuilt enzymes, and oxidation are factors that can lead to spoilage of agricultural commodities or food products. By reducing the temperature to -60 degrees Celsius, these processes slow down significantly and nearly halt altogether. While achieving a freezing point of -60 degrees Celsius is challenging and maintaining it even more so, conventional freezing methods typically freeze commodities to -18 degrees Celsius. Storing the product at this temperature until consumption can ensure its safety for up to a year.
There are several methods of commercial freezing used in the food industry. These methods include contact freezing, blast freezing, brine freezing, and cryogenic freezing. Contact freezers utilize trays or pans filled with water as a freezing medium to achieve fast freezing. Ammonia, Freon 104, and Carbon dioxide are commonly used as refrigerants in this system.
Blast freezing involves cooling and circulating air over the product to achieve freezing. While this is a conventional and economical method, it can result in slow freezing and quality loss. However, technological advancements have led to the development of quick freezing models like IQF freezers, which significantly reduce freezing time to just minutes.
While brine freezing may be considered an outdated method, it is still utilized in some developing countries for commercial ice production. Products are submerged in cold circulating brine for freezing, but this process can alter the taste of the product due to contact with the brine.
Cryogenic freezing, using liquid nitrogen as a refrigerant, is one of the most efficient freezing methods but is not commercially viable due to high costs and handling challenges. Despite this, it continues to be used in medical surgeries and organ preservation.
When it comes to freezing, the choice between slow freezing and quick freezing plays a significant role in maintaining product quality. Slow freezing processes may result in nutrient loss and deterioration of the product quality over time, while quick freezing methods help preserve nutrients and overall product quality.
In summary, the food industry employs various freezing methods to ensure the longevity and safety of commodities. Technological advancements have led to the development of more efficient freezing techniques, catering to the needs of commercial food production.
