New technology has made evaporative and vacuum cooling more efficient, and has led to enhanced product quality, higher productivity, and reduced costs. Foods such as potatoes, soups, sauces, fruits, chick peas, vegetables, and some meat products are suitable for evaporative cooling since most of them can be cooked and cooled in a single vessel, which minimizes handling. Retort capacities can be sized for up to 3,200-lb. batches of product or 50-800 gallon kettles, enabling large quantities to be processed easily.
Products can be taken directly from the field to a processing plant and cooled prior to distribution to foodservice outlets and retail stores.
Since evaporative cooling is the deaeration or removal of air from the product, it not only cools, but also improves product quality and increases shelf life by slowing bacterial growth. Evaporative cooling also eliminates the need for costly refrigerator rooms that have a large footprint and are expensive to operate.
Allpax retorts for processing raw product are designed with orbiting doors, which lift up and out of the way so the retorts can be loaded easily. This also reduces the retort’s footprint. The evaporative retorts feature 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.
The company’s integrated solution 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.
All the critical parameters are controlled by the Allpax control system, which features a 15-in. HMI color screen. The control system collects vital process data. Batch logs can be stored electronically and also printed.