Heat pump drying characteristics and mathematical modeling of chinese yam

The heat pump drying characteristics and mathematical modeling of fresh Chinese yam were studied. The effects of different factors such as the temperature and thickness of yam on heat pump drying characteristics were investigated. Moreover, the obtained experimental data were processed using the SAS 8.0 software for mathematical modeling, and a heat pump drying curve and a drying rate curve were obtained. When the temperature was higher and the slice thickness was smaller, the drying speed was faster, and the drying time of Chinese yam was shorter. The drying rate was significantly affected by the temperature, but less affected by the slice thickness. The heat pump drying model for Chinese yam was in good agreement with the Page model. There was a good agreement between the predicted and experimental values, indicating that this model can describe and predict the moisture dynamics of Chinese yam during heat pump drying process. The quality of heat pump drying products was compared with that of hot air drying products. Chinese yam dried by the heat pump showed good rehydration behavior, with a milky white color and a good sensory quality.