Do you use the terms frozen and frozen undifferentiated? Although often used one for the other, they nevertheless represent two very different cooling processes. Applied by industries, deep-freezing is done at a very low temperature and allows rapid cooling at the heart of the product. When freezing, the temperature is less cold and the process is therefore slower. Discover some key elements to better understand what differences lie between a frozen and frozen product.
The major difference between a frozen product and a frozen one lies in the cooling technique.
An industrial process, freezing consists in reducing the humidity level and the temperature of a food deeply and very quickly. This process involves exposing these foods to extreme temperatures, ranging from -30°C to -50°C and then reaching a core temperature of —18°C. All of this in just a few minutes.
Thus, thanks to this speed of transformation, the process forms ice crystals of minimal size. The advantage is that they avoid damaging the cells of each food and keep the nutritional qualities, such as vitamins, intact. You can then guarantee a shelf life of 8 to 36 months depending on the product.
This process makes it possible to best preserve the flavor, texture and nutritional qualities of the products. This is why manufacturers freeze fruits and vegetables directly after harvesting.
The freezing process is, for its part, the method of preservation by cold equivalent to freezing, but intended for individuals. Whether to keep a fresh and homemade dish or fresh food, they are placed in the freezer for longer storage.
In this process, the temperature of the food falls more slowly than when it is frozen. It then reaches -18°C, which makes it possible to stop any development of bacteria. This cooling also creates crystals, but of a larger volume. This can affect the quality of food.
Although these two processes perform extreme cooling of foods, there is a difference in product quality.
Because of the difference in speed between these two cooling processes, it is impossible to guarantee the same food safety. Indeed, as we saw earlier, the freezing process is slower than that of frozen products. There is therefore a greater risk of bacteria developing during this process.
In addition, the faster speed of freezing ensures better stability and preservation of the nutritional qualities of foods. The cells of the food thus remain intact, which allows it to maintain their freshness, flavors and textures. Meanwhile, the slower freezing process forms larger ice crystals, which can alter the taste, but also the texture of the products.
Although the freezing process is easy, fast, and economical, not all foods can be frozen. Among the products that are generally frozen, we find bread, meat, fish or even soups and cooked dishes in too large quantities. Depending on the type of product, freezing allows food to be preserved between 1 and 12 months.
For optimal freezing, however, be sure to respect certain precautions:
Thanks to home freezers designed to store food at a very low temperature, you can freeze a frozen product. Freezing time can range from 3 to 24 months. Once this limit is exceeded, there is a risk of altering the taste and texture of food. Frozen products from the industrial process follow very strict rules. It is therefore completely safe to freeze them, provided that your equipment works properly and keep them at the right temperature, namely between -12 and -18°C.
It is strongly recommended not to refreeze a thawed product.
In fact, during the defrosting process, the bacteria still present in the product take advantage of favorable conditions for their development caused by the warming of the temperature. During a long thawing at room temperature or rapid cooking at low temperature, their proliferation accelerates.
So, if you are refreezing products that have already started a defrosting process, the risk is that the process is slow. As we saw earlier, because of its slower process than freezing, freezing presents a risk of bacterial proliferation. In this case, as the product has already been in its thawing phase, the bacteria present still have time to develop a few hours before the core of the food reaches freezing temperature.
Eating a thawed and re-frozen product can have harmful health consequences such as food poisoning of varying degrees of severity. We have seen that when a food is frozen, it slows the development of the bacteria it contains. However, it is important to keep in mind that bacteria are still present. Thus, if the product is returned to room temperature, they can then develop and cause a risk of food poisoning and thus endanger the health of the consumer.
Respecting the cold chain is essential for a number of reasons. And this, at any point in the chain: during storage, or processing of products, but also during transport. A crucial but essential step, discover How to overcome this challenge in order to guarantee respect for the cold chain.
