After being washed, the wet vegetables are fed into the machine. They end up on an air permeable conveyor belt. Here, warm air is blown through the conveyor from below. This air is heated with the residual heat from other processes. This is an energy-efficient and cost-effective drying technique.
Water in food that is not bound to food molecules can promote the development of bacteria (yeasts and moulds). The term water activity (aw) refers to this free water. The salad dryer dries the product thermally so that practically 0% of the adhering moisture remains.
The less moisture that remains on the product, the lower the water activity.