Freezing of food materials is one of the oldest and basic methods of food preservation. It has its root way back in history as the mankind is using this method of food preservation from pre-evaluation period. This method has been utilized by humans from thousands of years. Previously, freezing food was as basic as encompassing it with blocks of freshly frozen ice to keep its temperature lowered. While with the passage of time, the innovation and updated techniques have changed drastically throughout the years, the basic theme continues as before, to lower down the food’s temperature to an appropriate degree where germs and microorganisms aren’t been able to live or exist, in this way expanding the life of the food.
Freezing method isn’t appropriate for all foods and freezing might cause physical and synthetic changes in some foods that might affect the nature of the defrosted material and may not leave it healthy to eat. There is a general view that quick freezing, and the development of little ice crystals, might offers some advantages that might be fruitful in nature. But this might not be valid for all foods. Like an example, some people say, freezing may affect the quality level of meat but there is no evidence that it has any considerable impact on its eating quality. Keeping all ideas in mind, some innovative freezing ideas and technologies are going through the process of innovation, development and research across the globe to lessen up freezing times and food quality.
Let’s have a look at some of the technology methods to freeze foods.
Flash Freezing
In early 1900’s before refrigerators were made history, Clarence Birdseye found discovered the advantages of freezing fish at low temperatures. Birdseye noticed that lower temperatures converted into a quicker freezing procedure implied the food could be preserved for longer period of time. In 1925, he developed a device which utilized a pressurized brine and water solution for freezing vegetables for transport. Rather than driving buyers to buy vegetables locally, they could now transport them throughout the country or state. Birdseye’s innovation was a mere achievement and was later on offered to the organization presently known as General Foods.
Impingement freezing
This technology implies to increase the surface heat transfer in air freezing systems and is considered one of the few recent innovations that has been commercially realized. Impingement is the process of directing a jet or jets of air at a solid surface to affect a change. The very high velocity (20 – 30 ms-1) impingement air jets, ‘breakup’ the static surface boundary layer of gas that surrounds a food product. The resulting medium around the product is more turbulent and the heat exchange through this zone becomes much more effective. This way food is preserved with a temperature change.
High pressure assisted freezing
This freezing method utilizes pressures of 200 to 400 MPa, and in particular ‘pressure shift’ freezing, has been attracting considerable scientific interest in recent years, and is a way of ease and efficiency when it comes to food preservation at commercial level.
Magnetic resonance assisted freezing: A Japanese protected framework called CAS (Cells Alive System) freezing, which includes variable magnetic fields, has been promoted by ABI (Japan) for upgraded freezing and frozen stockpiling of foods. The CAS innovation proves to “hold the surface and kind of food by improving super cooling of the item. These are some of the latest technologies to preserve foods and serve it at long.
