Individual Quick Freezing, usually abbreviated IQF, is a descriptive term for freezing methods used in the food processing industry. The food is in individual pieces, and is frozen quickly. Products commonly frozen with IQF technologies are typically smaller pieces of food, and can include

berries A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit, although many pips or seeds may be present. Common examples are strawberries, raspb ...

fruits In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particula ...

and

vegetables Vegetables are parts of plants that are consumed by humans or other animals as food. The original meaning is still commonly used and is applied to plants collectively to refer to all edible plant matter, including the flowers, fruits, stems, ...

both diced or sliced, seafood such as

shrimp Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...

and small

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

meat Meat is animal flesh that is eaten as food. Humans have hunted, farmed, and scavenged animals for meat since prehistoric times. The establishment of settlements in the Neolithic Revolution allowed the domestication of animals such as chic ...

poultry Poultry () are domesticated birds kept by humans for their eggs, their meat or their feathers. These birds are most typically members of the superorder Galloanserae (fowl), especially the order Galliformes (which includes chickens, quails, a ...

pasta Pasta (, ; ) is a type of food typically made from an unleavened dough of wheat flour mixed with water or eggs, and formed into sheets or other shapes, then cooked by boiling or baking. Rice flour, or legumes such as beans or lentils, are som ...

cheese Cheese is a dairy product produced in wide ranges of flavors, textures, and forms by coagulation of the milk protein casein. It comprises proteins and fat from milk, usually the milk of cows, buffalo, goats, or sheep. During production, ...

and

grains A grain is a small, hard, dry fruit (caryopsis) – with or without an attached hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and legume ...

. Products that have been subjected to IQF are referred to as Individually Quick Frozen.

Benefits

One of the main advantages of this method of preparing

frozen food Freezing food preserves it from the time it is prepared to the time it is eaten. Since early times, farmers, fishermen, and trappers have preserved grains and produce in unheated buildings during the winter season. Freezing food slows decompositi ...

is that the freezing process takes only a few minutes. The exact time depends on the type of IQF freezer and the product. The short freezing prevents formation of large ice crystals in the product’s cells, which destroys the membrane structures at the molecular level. Pruthi, J. S. (1995). "Quick Freezing Preservation of Foods: Foods of animal origin", p.14. Allied Publishers Limited. . This makes the product keep its shape, colour, smell and taste after defrost, to a far greater extent. Another advantage of IQF technology is its ability to separate units of the products during freezing, which produces a higher quality product compared to

block freezing Block or blocked may refer to: Arts, entertainment and media Broadcasting * Block programming, the result of a programming strategy in broadcasting * W242BX, a radio station licensed to Greenville, South Carolina, United States known as ''96.3 ...

. This is important for food sustainability, as the consumer can defrost and use the exact quantity needed. A growing demand in IQF products is registered at global level due to the higher quality of these products and to the benefit of having separately frozen pieces. IQF is also a common pre-treatment for

freeze-drying Freeze drying, also known as lyophilization or cryodesiccation, is a low temperature dehydration process that involves freezing the product and lowering pressure, removing the ice by sublimation. This is in contrast to dehydration by most conve ...

food because both processes preserve the size, taste and cell structure of the food better than methods such as traditional

or air drying.

Methods

There is a range of IQF technologies, but the main concept is to transport the product into the freezer with the help of a processing line belt or infeed shaker. Inside the freezer, the product travels through the freezing zone and exits the other side. Product transport inside the freezer uses different technologies. Some freezers use transport belts similar to a conveyor belt. Others use bed plates that hold the product, and an asymmetrical movement makes the plate advance by itself through the freezer.Heldman, Dennis R. Hartel, Richard W (1997). "Principles of Food Processing", p. 123. Food Science Texts Series. . There are 2 main IQF technologies: mechanical IQF freezers and cryogenic IQF freezers. Mechanical IQF freezers work on the principle of cold air circulation, which flows from underneath the bed plate or transport belt with the help of fans. The cold airflow passes through the pieces of product in circular motions while the product is also advancing through the freezer towards the exit. The design and efficiency of this type of IQF freezers varies among manufacturers who seek to find the perfect balance of aerodynamics for an optimal freezing result. This technology has seen impressive improvements and developments during the past 20 years, being suited for an increasing range of products.Peterson, Rand
"Cryogenic vs. Mechanical Freezers: The Best Uses for Each Method"
''

Stellar Food For Thought Stellar means anything related to one or more stars (''stella''). The term may also refer to: Arts, entertainment, and media * ''Stellar'' (magazine), an Irish lifestyle and fashion magazine * Stellar Loussier, a character from ''Mobile Suit Gu ...

''. February 18, 2016. Retrieved on July 21, 2016. Cryogenic IQF freezers immerse the product in

liquid nitrogen Liquid nitrogen—LN2—is nitrogen in a liquid state at low temperature. Liquid nitrogen has a boiling point of about . It is produced industrially by fractional distillation of liquid air. It is a colorless, low viscosity liquid that is wide ...

at very low temperatures, freezing it rapidly while continuously moving the product to avoid block or lump formation. Although this method shows good freezing results, it might lead to higher processing costs per weight of product due to the cost of the liquid nitrogen required.

References

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External links

IQF freezing technology
Food processing