Vacuum cooling has become widespread in the food industry, but is more used in the bakery industry.
The principle of vacuum cooling is based on the evaporation of the moisture (water) contained in the product at a pressure below atmospheric pressure, by lowering the temperature (point) of the boiling point of water.
The product after thermal processing has not only a high temperature, but also contains hot liquids in itself.
Vacuum cooling takes on several functions at once:
- After-baking of the product, as during the process of vacuum cooling, additional evaporation occurs, and as a consequence, secondary steam is “removed” from the surface and pores of the product, during which rapid cooling occurs.
- Rapid product cooling
- By changing the depth of the vacuum - "controlling" of the characteristics of the product, such as vacuum cooling of bread, when high or low residual pressure affects the crumb and crust. Some products require a crispy crust, while others require a soft crust, this can be achieved by adjusting the vacuum depth.
There are several categories of benefits of vacuum cooling:
- The presence of vacuum cooling allows a 90% reduction in the area used in the convective method, or the layout of the product on the working surfaces, no need for spiral cooling towers in continuous production
- Reduce energy consumption for baking by at least 40%, since the after-baking process is already carried out not in ovens or convection ovens, but in vacuum coolers.
- Vacuum cooling allows you to increase productivity by 40%, as it reduces both the time of thermal processing of products (cooking, after-baking), as well as the time for subsequent cooling.
These advantages, first of all, will interest the owners of large industries.
But vacuum cooling has many advantages that are also of interest to small bakeries or food processors, such as the impact on product quality.
- Almost every manufacturer of bakery products knows that vacuum cooling gives bread fluffy, volume. The product looks attractive to the consumer, compared to bread after the conventional convective cooling method.
- But not only the appearance changes after vacuum cooling, for example, after vacuum cooling of sushi rice, it becomes sweeter, the taste becomes rich. In fact, vacuum-cooled rice continues to cook in the process of "cold" thermal processing. This possibility allows you to preserve the original individual taste of the product, to saturate it without losing useful and organoleptic properties.
- The product, after vacuum cooling, increases its resistance to mold, that is, the shelf life of the product increases. As an additional benefit, this is the elimination in the process of processing of possible contamination of products at the stage of cooling under the atmosphere. The vacuum not only cools the product, but in its own way "disinfects", removing water, steam or air from the product, which contain various pathogens.