A study on decompresses heat pump dryer for drying of shiitake mushrooms at medium temperature

This study developed a drying method and a dryer that are optimized for shiitake mushrooms. They are mainly being cultivated and consumed as food and medicine in Korea, Japan, China, and Southeast Asia. They generally contain lots of moisture. For this reason, the use of a dryer causes problems such as decomposition and spoilage, and natural dry processing is preferred. To resolve these problems, various drying methods have been proposed (e.g. hot air drying, heat pump vacuum drying) but there has been a difficulty in maintaining a medium-temperature range of 30 to 40°C, the optimal temperature environments for retaining their main components. The study developed a 2-stage decompresses resistive heat pump dryer that can operate also in medium-temperature environments - existing decompresses heat pump dryers have been able to operate only in high-temperature environments. A dryer optimized for shiitake mushrooms that are being produced and distributed in large quantities was proposed, and the utility of the machine was proved through experiments.