Consumers are interested in the textural changes of IQF vegetables compared to fresh ones and ask themselves whether the freezing process involves a loss of nutrients. Such questions can be answered only by studying the effect of freezing on various plant tissues.

Most vegetables contain a large quantity of water, stored in the cell walls, which are responsible for the vegetables' texture and support structure. Basically, freezing vegetables means freezing the water inside the cell walls.

During the freezing process, water expands and forms ice crystals that break the cell walls when using traditional, slow freezing methods.

The key to preventing and controlling the cell wall rupture is to freeze vegetables as quickly as possible.

By comparison, during the IQF process (Individual Quick Freezing), the water inside the cell walls is transformed into a large number of small ice crystals, which create less damage. Therefore, IQF vegetables will have a far better texture than products which are slow frozen.

Freezing vegetables inside the OctoFrostTM IQF tunnel is a very effective food preservation method, which means the IQF vegetables will have better nutritional value than fresh ones. However, in order to obtain this result, producers must comply with all the necessary procedures during the IQF freezing.

How processors can avoid the dehydration of IQF vegetables

Dehydration is one of the main problems that need to be avoided during IQF freezing, since this process is less obvious and more difficult to quantify but has a great economic impact. Dehydration occurs as a result of the loss of water vapors, when vegetables are exposed to air. In the case of IQF vegetables, dehydration is significantly reduced due to two factors.

Firstly, IQF vegetables benefit from the short period of time in which the water is evaporating at a higher rate. However, in order to achieve fast freezing, cold air is not enough. The air must be evenly distributed over the surface of the product, with the help of an efficient airflow, and this can be achieved inside the OctoFrostTM IQF tunnel freezer.

Secondly, if the temperature of the product is reduced rapidly, the rate at which water is transferred from the product into the air (the evaporation rate) will also be significantly lower.

The OctoFrostTM IQF tunnel freezer is equipped with perforated bedplates and high-performance fans, which distinguish it from traditional freezing solutions. Inside this freezer, the movement of the bedplates and the unique airflow help to maintain an efficient separation of IQF vegetables and to protect even the most delicate products, such as broccoli, asparagus, or spinach.

Inside the OctoFrostTM, IQF vegetables benefit from the optimal airflow and pressure ratios during the freezing process, due to the aerodynamics controlled and adjusted in each freezing zone. This allows for a minimum dehydration of IQF vegetables, which means they will maintain their natural appearance, with a minimum number of fines or lumps.

Moreover, snow formation is prevented inside the OctoFrostTM IQF tunnel freezer, which translates into a valuable uptime between defrosts.