The freezing process is a combination of the beneficial effects of low temperatures at which microorganisms cannot grow; chemical reactions are reduced, and cellular metabolic reactions are delayed. Michael Hase, area sales manager with Heinen, explains features of freezing equipment supporting these processes.
The freezing process normally takes place at the end of the processing line, meaning that freshly-made products are directly then frozen, to keep their properties and freshness. Freezing times are product specific, so they will vary according to the types of baked goods.
Longer freezing times trigger weight loss. Quick freezing means less weight loss of the product. For example, smaller products can be frozen in a matter of minutes, while for more delicate textures, like cakes, freezing can be a matter of hours. Failing to maintain correct freezing times can damage the product. The best indicator of the correct timings for each type of products is experience, which is what makes the process extremely product-specific and challenging.
Innovations in Continuous Freezing
Heinen shares how continuous freezing can be optimized when handling baked goods, a processing sequence taking place right after the production line, and before packaging. As each product has its specific freezing time, freezing times need to be tested and accurately determined before sizing a freezing system. The heat content of the product about the undergo freezing is also a factor that must be known as it impacts the specifications required from the continuous freezer.
According to how hot the products are, the energy needed to cool and freeze them can be calculated. Airflow and air velocity also influence this. Correctly evaluating all these factors will determine the appropriate freezing process.
In the case of versatile lines, manufacturing different types of products, more variables must be taken into consideration to determine freezing.
For example, in the case of a line producing dough ahead of the freezer, making croissants or Danish pastries, Heinen have to calculate what would be the size of the machine, taking into consideration all the products. The most challenging product is the one that will determine the specifications/settings of the freezers, and all the remaining ones in the manufacturer’s production line will benefit from using the same machine without any problems. Such an example of a more difficult product is that of croissants: if a line fits normal croissants and also filled products (with chocolate or cream filling, jam or fruit), the fruit ratio must be assessed in relation with the dough, so specific product know-how is key.
In addition to these factors that determine requirements from the freezing equipment, freezers can be customized according to production capacities (kg/hour to be frozen), the width of the line in front of the freezer, the space available in the production facility.
Production cycles (uptime hours of the production line, which could range from 8, 16 or 24/7) also play a role in determining the configuration that best suits the plant.
Read more insights from Heinen on this topic, in Asia Pacific Baker & Biscuit, Winter, out soon.