"Creative Commons Chickpeas" by Martina_Nolte is licensed under CC BY 3.0

Retorts for evaporative cooling of large batches of raw product can be used to eliminate the transportation and refrigeration expenses of traditional cooling process, says the manufacturer. Foods such as potatoes, soups, sauces, fruits, chick peas, vegetables and some meat products can be processed via evaporative cooling because they can be cooked and cooled in a single vessel, which minimizes handling.

Retort capacities for evaporative cooling retorts from Allpax Products, Covington, La., can be sized for up to 3,200-lb batches of product or 50- to 800-gal kettles, enabling large quantities to be processed. Furthermore, products can be taken directly from the field to a processing plant and cooled prior to distribution.

As Allpax notes, when foods are cooked in traditional ways, they have to be transported to refrigerated rooms. Evaporative retort cooling works by the deaeration — or removal of air — from the product. This method cools, improves product quality and increases shelf life by slowing bacterial growth.

Allpax retorts for processing raw product are designed with orbiting doors that lift up and out of the way so the retorts can be loaded. The company's evaporative retorts have double doors: one door is for the entry side and one for the exit side. A sealed partition is placed midway in the retort. The product being processed is loaded into trays or baskets and placed in the entry side of the retort, and the door is closed. Typically steam is used to heat the product, processing it to a given temperature. Once sterilized, the food is conveyed to the cooling side of the retort. Evaporative cooling, which lowers the atmospheric pressure in the vessel, quickly evaporates the water off the product and cools it. Once the process is complete, the exit-side door is opened and the sterilized and cooled product is removed.

Allpax’s system controls the vacuum ejector systems via a large valve on top of the retort and a transmitter that measures the vacuum and other inputs and outputs on specific valves. The control system integrates the outside components, allowing for the monitoring and modulating of the vacuum, temperature, and pressure to ensure that the user’s desired outcome for the finished product is achieved.