Preserving Product Qualities Through Precise Regulation of Process Humidity

Potatoes have a lot of water when they are harvested. In the production of snacks, value-added foods, and byproducts, moisture is gently removed. The formation or preservation of desired features, such as maintaining taste, color, and texture, is made possible by precise regulation of drying and process humidity.

Dehydration can provide a long shelf-life, for dehydrated potato slices, dices, and shreds, while retaining fresh potato flavor and texture when reconstituted.

“For pre-form product and retrogradation, drying with integrated cooling can achieve the perfect surface texture for the forming of co-product for hash brown-type products. For convenience and frozen food processors, a dehydro-frozen dryer can effectively process value-added potatoes and vegetables, often diced for soups and stews,” Ron Walunas, Senior Applications Engineer at Buhler Aeroglide Corporation mentioned.

A multi-stage, single-pass conveyor dryer can effectively handle potatoes for any application, including drying, roasting, and dehydration. As the product goes through various zones with individually controlled temperature, humidity, and airflow, processing uses air to transmit heat and remove moisture.

Impingement processing provides a homogeneous airflow across the whole conveyor for roasting and color development, ensuring consistent color at high volumes. The oven edge effect is eliminated by the quick, uniform high-heat transmission provided by high-velocity impingement air tubes over the conveyor bed. Through high-speed pinging against the surfaces, impingement systems remove the boundary layer surrounding the product.

When compared to lower velocity convection or via air systems, this significantly accelerates heat transfer, cutting the time required for the operation by at least 50%. Airflow and temperature from above and below the conveyor are accurately controlled by dual impingement systems, which are designed for this purpose.

To ensure a uniform drying process at each stage of processing during dehydration, a multi-stage drier with transfer sections between stages will gently reposition goods. The multi-stage processing method for pre-formed products offers flexibility in cases when additional cooling time is required for starch gelatinization. A multi-stage setup provides the operational flexibility required to adjust process air, humidity, airflow rate, and retention time at different phases of processing for dehydro-frozen products, where the focus is on flavor concentration and water removal.

You can read the rest of this article in your complimentary e-copy of Issue 2 of Potato Business Dossier 2023, which you can access by clicking here.