IQF fruits represent an extensive and important food group in our contemporary world, which helps us adapt to the fast tempo of our lives. The evolution of technology has made individually freezing fruit possible, and it's reassuring to know that no matter what season, you can find precisely the IQF fruit you desire. IQF fruits consumers expect to get the highest quality depending on the purpose of using them. If the fruit is to be consumed without any further processing after thawing, the texture is essential compared to use as a raw material in other industries.

For freezing IQF fruits conventional freezing methods are not recommended, because they have a tendency to destroy the cellular structure in fruit tissue. Unlike vegetables, fruits do not have a fibrous structure that can oppose this destructive consequence. Also, fruits to be frozen are picked when they are completely ripe, and their structure is very fragile. Moreover, fruits have gentle flavors that can be harmed by fluctuating temperatures. Another challenge is to preserve the natural color of the IQF fruits. Therefore, adequate processing is essential for all steps involved in the freezing process, from harvesting to packaging.

The appropriate collecting time

The attributes of raw products are fundamental in determining the quality of the IQF fruit: the genetic makeup, climate of the growing area, type of fertilization, and maturity of harvest. Mechanical harvesting is not recommended because it generally causes crushing the fruit, which results from a wide range of maturity levels of fruits. Instead, hand-picking provides a gentler handling and maturity sorting of fruits. However, in most cases, it is not economically efficient compared to mechanical harvesting due to high labor cost.

In most cases, harvesting fruits for commercial use is a difficult process. Pressure tests applied to fruits are required, in order to determine whether a fruit has reached optimal maturity for harvest. Another characteristic used to determine maturity is the color, considering that as the fruits mature the color becomes darker.

Before freezing, some fruits are placed in a controlled atmosphere storage. In principle, a controlled atmosphere high in carbon dioxide and low in oxygen content, slows down the rate of respiration, which may extend shelf life of any respiring fruit during storage. However, fruits don`t have time to ripen substantially after collecting, since most of them are picked as near to eating-ripe maturity as possible, which is beneficial to obtain remarkable IQF fruits.

Pre-process handling

The quality level of the raw materials before freezing is the major consideration for procuring superior IQF fruits. It is recommended that fruits are pre-processed prior to the freezing process in terms of peeling, slicing or cutting. Fruits that require peeling before consumption should be peeled prior to freezing. Peeling is done by scalding the fruit in hot water, steam or hot lye solutions. Before the peeling it is advisable to check what impact it has on the quality of the IQF fruit.

In the case of large fruits, freezing result may be improved if the size of the fruit is reduced. The smaller the pieces, the shorter the freezing time which decreases cellular damage in fruit tissue. Fruits like banana, mango or kiwi are some examples of large fruits generally cut into smaller cubes or slices before the process of IQF freezing.

Also, there are fruits that require blanching before freezing. The procedure of blanching is used to inactivate the enzymes which cause changes in color, odor, flavor, and nutritive value, however, heat treatment causes loss of such characteristics in fruits. Therefore, only a few types of fruits are blanched for inactivation of enzymes before introducing them into the IQF freezer. The loss of water-soluble minerals and vitamins during blanching should be minimized by keeping blanching time and temperature at an optimal level.

At this moment, the fruits are ready to enter the IQF tunnel freezer and to become remarkable IQF fruits, with a natural appearance, size, color, and shape.