Some examples:Heating and cooling of milk
For example, milk must be kept within acceptable temperature ranges for transport, storage and processing, until reaching the end product and even after packaging. Failure to meet these temperature ranges can alter the features of the materials and thus result in throwing it away so as not to compromise the health of consumers.
Pastorization requires heating and cooling, often accompanied by heat recovery to reduce energy consumption.Cooling for margarine
The margarine production, during the crystallization phase, requires considerable cooling to reach the final result.
The control of fermentation in the wine sector and some processes such as cooling induced to favor the storage of tartaric acid or carbonic maceration, in addition to the normal cooling to slow down/stop the fermentation, require above all cold administration.Heating and cooling of food and ice creams
Food creams and ice creams are produced in similar ways by “scraping” the product from cooled surfaces (scrapers or mixing machines).
Vacuum cooking of pastry creams
An interesting application is vacuum cooking, which allows to produce from pastry creams to rags to jams to cheese to spread, with very interesting results from an organoleptic point of view.
Similar arguments can be made for almost any foodstuff.Chocolate heating and cooling
Chocolate production requires mixing, heating and final cooling before packaging.Extrusion of pasta, cereals, snacks
Each application has peculiar characteristics but the general rules are usually the same.
In some cases, production involves the heating of food solutions in heated and cooled tanks through cavities (for example sugary solutions to spray on cereals). In other cases, the process is a true extrusion, with problems and working parameters similar to those of extrusion of plastics.
Almost always, heat exchanges occur through fluid fluids, the preferred one being water.
Where temperatures are high and you have to work on cavities is normally used diathermic oil.
Where temperatures are low you have to add glycol (usually propylene) to water.