To produce, pack and store food, many different cooling systems have to be used (vegetables, margarine, ham, cheese, ice cream, etc.)
Milk, for example, must be kept within acceptable temperatures during transport, storage and processing to pack, bottle and store it until it is sold. If the temperature is not under control all the food products could be damaged and therefore they should be thrown away not to result in very dangerous risks for human health.
This is true for most of food products. Sometimes production requires heating and cooling of food solutions in reactors through hollow jackets or heat exchangers. Some other processes are very similar to the extrusion processes in plastic industry and accordingly they also require cooling and/or heating.