Researchers develop faster, less costly way to process walnuts
According to AgResearch magazine, scientists at the U.S. Dept. of Agriculture’s Agricultural Research Service (USDA ARS) have developed a method that uses infrared technology to improve commercial walnut processing—particularly drying—to reduce energy costs and deliver high-quality products.
According to AgResearch magazine, scientists at the U.S. Dept. of Agriculture’s Agricultural Research Service (USDA ARS) have developed a method that uses infrared technology to improve commercial walnut processing—particularly drying—to reduce energy costs and deliver high-quality products. Walnut drying is expensive and energy intensive, according to Zhongli Pan, ARS engineer. The current hot-air drying method takes more than 24 hours to dry walnuts and uses a significant amount of natural gas and electricity. Pan believes infrared—a form of intense light that’s felt, but not seen—will dry walnuts faster and is less expensive.
The new drying process, developed by Pan and his team at ARS’s Western Regional Research Center, includes three new steps: Hulled, in-shell walnuts are separated into two groups with different moisture contents; then pre-dried with infrared heating; and followed with regular hot air drying. In experiments, the new process saved up to 25% of the natural gas and electricity needed to dry walnuts. In addition, the infrared drying process quickly removed moisture from the surface and shell of walnuts, reducing total drying time by 35%. In addition, infrared drying prevents over- or under-drying of walnuts.