Flash freezing is the process where objects are frozen in a short period of time by subjecting them to extremely low temperatures. This is especially used in the food industry as a quick and convenient way to preserve fruits and vegetables. This process is made possible by rapid exchanges of thermal energy during its procedure. However, this process contains some environmental drawbacks to its many benefits which questions its use in our food supply chain. Flash freezing takes fresh fruits and vegetables directly after a harvest into a large chamber where they undergo a process called blanching.
Blanching is where you steam or boil vegetables over a very short period of time, where it is immediately dumped into extremely cold water with temperatures below -18?. The reason for this sudden shock of temperature is to inactivate chemical compounds called enzymes that causes the loss of color, nutrients, flavor, and causes spoilage. Blanching also helps to destroy microorganisms on the surface vegetables to ensure the food safety of the product. After this step has been completed, the vegetables continue their freezing as quickly as possible using a flash freezing freezer.
Flash freezers are equipped with very large spaces separating the trays to allow cold air to be pumped in continuously by the fans behind the racks.Electrical energy is being converted into kinetic energy as the electricity provided is being used up to turn the fan within the freezer. Some energy is given off to sound energy and friction as thermal heat is produced from the moving parts. Air is then pushed by the fan and passes over the refrigerant called HFC-134a. The cold air blows over the vegetables resulting in thermal energy being gained as the heat is being absorbed by the passing air. As the air returns back to the fan, thermal energy is passed over to the refrigerant, where it absorbs the heat as it changes from a liquid to a gaseous state. Work from a compressor then puts the gas under high pressure releasing plenty of thermal energy.
All the thermal energy created by compressing the gas is then removed from the system by a second fan, allowing the cycle to continue and the cooling process to work. Flash freezing deeply affects the food supply chain. The frozen food market has become the largest and most dynamic sectors of the food industry.
Frozen foods are being consumed all over the world causing the industry to grow to over 75 billion US$. This is because flash freezing technology is one of the most convenient and easiest methods of food preservation.The average shelf life for almost all frozen vegetables is eight to 12 months, while fresh is only a couple weeks. Also, it is used to make ready to eat meals, pastries, ice cream, and many more food products.
However, food that is flash frozen and thawed is almost identical to the fresh product making it a huge benefit to restaurants because they can take advantage of seasonal bounty and preserve it with minimal losses in quality and yield. It also extends the preservation of fruits during off-seasons. Frozen fruits are transported to remote markets that could not be accessed with fresh fruit.
Freezing preservation now makes year-round processing of fruit products possible, such as jams, juice, and syrups from frozen fruit and pulps. Flash freezing contains some environmental benefits and drawbacks. Flash freezing has some negative impacts on the environment due to the use of refrigerant HFC-134a in the freezer. HFC-134a is an important greenhouse gas with 1 kilogram of HFC134a equivalent to 1.18 tonnes of carbon dioxide which accelerates global warming.
However, flash freezing benefits the environment as well in the form of reducing wastage. Up to 40 percent of all the food we produce ends up in the trash meaning that we overwork the earth, process, and transport food that will end up in the garbage. With flash freezing, the produce doesn’t need to be picture-perfect either due to the blanching and chopping that it undergoes.
The visually appealing ones that are still good, go in with the perfect ones, without the need to establish a separate chain for selling the rejects. Furthermore, food made industrially can be made and refrozen to keep for a longer period of time without going bad such as pastries and baked goods. Finally, food can be stored in freezers in households for longer periods of time then fresh produce in the fridge.
In conclusion, flash freezing contains some environmental benefits and drawbacks but it is crucial to the food supply chain.