IQF

Individual Quick Freezing usually abbreviated IQF is a freezing method used in food processing industry. Products commonly frozen with IQF technologies are typically smaller pieces of food products and can range from all types of berries, fruits and vegetables diced or sliced, seafood such as shrimps and small fish, meat, poultry and even pasta, cheese and grains.. Products that have be subjected to IQF are referred to as Individually Quick Frozen or IQF'd

One of the main advantages of this method of preparing frozen food is that the freezing process takes very short time (only a few minutes with the exact time depending on the type of IQF freezer and product frozen). The short freezing time does not allow the formation of large ice crystals in the product’s cells which would destroy the membrane structures at molecular level . This makes the product keep its shape, colour, smell and taste after defrost, at a far greater extent.

Another significant advantage of IQF technology is its ability to separate the products during the freezing process, which results in products of higher quality when compared to those which are block frozen for example. This advantage is also important for food sustainability as it allows the defrost and use of the exact needed quantity as opposed to defrosting a bigger block and dispose of the unneeded or unused portion. 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 comes out on the other side. The transportation of the product inside the freezer can be achieved through different technologies depending on the IQF freezer’s brand. There are solutions based on transportation belts inside the freezer which is similar to a conveyor belt. Other latest innovations include bed plates on which the product lands and an asymmetrical movement is used for making the product advance by itself in the freezer.

There are 2 main IQF technologies: mechanical IQF freezers and cryogenic IQF freezers.

The mechanical IQF freezers work on the principle of cold air circulation which is pushed from underneath the bed plate/transportation belt with the help of fans. The cold airflow keeps passing through the pieces of product in circular motions while the product is also advancing through the freezer towards the exit end. The design and efficiency of this type of IQF freezers varies among manufacturers who are trying 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.

In the case of the cryogenic IQF freezers the product is emerged in liquid nitrogen at very low temperatures for instant freezing, while also continuously moving the product in order to avoid block or lump formation <ref name=Peterson /ref>. Even though this method shows good freezing results, it might lead to higher processing costs per kg of product due to the large amount of higher cost liquid nitrogen required.

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