To shed light on this discussion, it was necessary to ask Christophe Batanero, commercial director of Panem International, about the preconceived ideas surrounding this subject.
His answer is unequivocal: they do indeed exist, particularly on one key element, time management.
"Deep freezing is increasingly used because if it is done properly it does not alter the product at all. For this reason, however, it should not be considered as a secondary step, at the end of production, whose sole objective would be to be as short as possible," he explains.
The idea that rapid freezing guarantees quality seems deeply ingrained in the collective consciousness. However, this notion needs to be qualified. Indeed, it is primarily freezing at temperatures around -18°C that causes structural changes, as the temperature decrease is slower and thus impacts product quality. Conversely, mechanical freezing and cryogenics are two rapid processes that better preserve the product's characteristics.
“Mechanical freezing is well-suited to semi-industrial production and processed products. Cryogenic freezing is more often used on very high-speed lines. It works well with small products that contain a lot of water,” explains Christophe Batanero. He adds: “When thinking about refrigeration, it’s important to clearly distinguish between a blast chiller, a blast freezer (or tunnel), and a negative temperature storage cabinet.”.
A blast chiller rapidly lowers the temperature of a hot product to limit bacterial growth. A blast freezer or tunnel, on the other hand, rapidly and in a controlled manner lowers the core temperature, generally to around -20°C. Finally, a negative temperature storage cabinet maintains the product at its ideal storage temperature.
Regarding freezing time, Christophe Batanero emphasizes that "weight is not the only criterion to consider. The nature of the product, its specific heat capacity, its temperature, as well as environmental factors such as the distance from the refrigeration unit, must be factored into the calculations to determine the ideal time." In freezing, as in meditation, the process is more important than the final result. Optimal freezing relies on the balance between the nucleation rate (that is, the number of water crystals that form) and the growth rate of these crystals. While the former depends on the speed of cooling, the latter is influenced by the ability to dissipate heat around the crystals and by the properties of the product in question.
Finally, one last element comes into play: the stage of processing at which freezing occurs. In baking, for example, it is possible to freeze a raw, partially risen, or already cooked product, each cycle requiring specific adjustments.
Therefore, freezing requires a comprehensive approach. "It may even necessitate some adjustments to the original recipe," emphasizes Christophe Batanero. But its advantages are undeniable: it allows for increased production capacity, the opening of new sales outlets, and the acceptance of additional contracts, all to better satisfy food lovers.
