What are the differences between IQF and Cold Store freezing?

November 14, 2016

IQF is a technology that allows the freezing on an individual piece of product separately from the others. Due to this, the quality of the finished IQF product is superior compared to the one of a product frozen by cold store freezing.

The main difference is the size and quantity of the frozen product; cold store freezing is used for large volumes of bigger sized products such as whole chicken or packed meat. IQF, on the other hand, is ideal for freezing smaller products such as small fruit, fruit cubes, vegetables, cheese, pasta, etc.

Using IQF technology will significantly reduce the ice formation on the product, due to the fact that the product is frozen fast this leads to much smaller ice crystals compared to cold Store Freezing. Slow freezing causes large ice crystals to form, and this affects the integrity of cells, stretching the membrane, the larger the crystals the more damage the product will suffer. The deterioration is irreversible, meaning that the texture of the product will not return after thawing. With IQF there is a minimal formation of ice crystals, and this will help the product keep its texture until first defrost.

Products from cold storage freezing also experience a lot of drip loss, loss of texture and nutrients after the first thaw. These are not the only issue caused by ice crystals, another problem caused by this ice formation is dehydration. Due to the length of the freezing process, the product suffers from water loss through sublimation (when water turns to gas from solid form), speeding up the freezing process can help the reduction of dehydration, this is why by using IQF technology, the dehydration rate is somewhere between 0.3% to 2% whereas with cold storage freezing the dehydration rate is frequently somewhere between 5% - 10%, this is a direct loss of the quality of the product.

The loss in color is another characteristic frequent to cold storage freezing, even if the color is more vibrant that of the frozen product with cold storage freezing; when it thaws, the product loses the vibrant color and gets a more grayish tone. This discoloration can be avoided using IQF technology as the product has a more natural color that stays unchanged after the first defrost.

When we put our food in the freezer we notice that it tends to stick together when frozen. This issue is also observed in cold storage freezing when products form large ice formation around themselves and get stuck to each other requiring more force to disconnect them. This also depends on a lot of the size and the stickiness of the products. During the IQF process, the products are frozen much faster and separate from each other, which do not allow them to stick together and will remain like that until first defrost. This is very useful especially if the product is to be packaged using the multi-head weighing equipment.

By using IQF technology, the products keep their initial shape without any damage to the surface, and have a higher shelf life. This is because the product does not get exposed to much air in the IQF freezer.

Using cold storage freezers requires more manpower for handling boxes or trays if the products are frozen in a big block of ice and require mechanical separation. Cleaning, handling, and repairing of trays is time and manpower consuming.

Because the products get in contact with the people, there is a considerable risk for contamination when freezing products in a Cold Store freezer. With a modern in-line process and the IQF freezer, it is possible to achieve zero contact between the product and the human being.

Overall using the IQF instead of cold storage freezing is more cost efficient. The benefits are:

1. Better quality products

2. Better texture

3. The final product has more nutrients

4. Better aspect

5. Less money loss from the weight loss during dehydration.