UV-A Light Dehydration of Foods

Benefit

Traditional food dehydration systems remove moisture from food materials using physical mechanisms such as evaporation, diffusion, and sublimation (e.g., hot-air drying, sun drying, osmotic drying, vacuum drying, and freeze-drying). Although these methods can be effective, they may require excessive amounts of time, capital, or energy. Excess energy usage may induce negative effects on both the food and the environment, such as enzymatic and nonenzymatic browning (caramelization), protein denaturation (which may diminish nutritional quality), loss of micronutrients (such as vitamins), pyrolysis, gelatinization of starch, uneven heating or overheating (which can lead to hardening or cracking), and emission of harmful greenhouse gases. The use of UV-C light has been shown to be low-cost and effective, but the FDA reports that exposure to UV-C radiation can cause serious health problems in humans, such as cataracts, severe burns, and skin cancer.

To improve upon existing food dehydration methods, USU researchers developed a method of food dehydration using UV-A light in a closed chamber with a vacuum air flow source, using an ideal combination of UV-A light intensity, input air conditions (relative humidity and temperature), and speed of air removal. An apparatus includes a light source configured to expose food in a chamber to UV-A light, an air flow source to provide a relative humidity of less than 50%, and a controller to remove food when it reaches the desired level of moisture. This method requires less energy than some traditional methods, which makes it more cost effective and easier to install, while preserving nutrients. In addition, UV-A light is considered the safest of UV rays which lowers risk for human use. Chemical additives required by other methods are eliminated by using this UV-A light method.

Food dehydration in general serves to prevent food spoilage, prolong shelf life, and reduce mass and volume, which in turn reduces space and costs for food storage and transportation. Researchers expect that commercializing UV-A dehydration will improve upon these benefits by decreasing energy and chemical usage, reducing health risks and environmental impact, and lowering installation and maintenance costs, while preserving the nutrients and color of the food.

Market Application

This technology may be applied in the Food Processing Equipment market as a tool for dehydrating foods.