Zhang Weipeng, Chen Chang, Pan Zhongli, Zheng Zhian
School of Artificial Intelligence, Beijing Technology and Business University, 11 Fucheng Road, Beijing 100048, China.
Department of Biological and Agricultural Engineering, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA.
Foods. 2021 May 1;10(5):992. doi: 10.3390/foods10050992.
The objective of this study was to develop an efficient drying technology for poria cubes in order to improve product quality. Poria cubes were dried using different methods, including air impingement drying, infrared-assisted air impingement drying, vacuum drying, two-stage vacuum drying, and infrared-assisted air impingement drying. The results were compared with those from hot air drying. For the two-stage drying, the tested conditions were the first stage of vacuum drying with temperatures between 65-85 °C and a switching moisture ratio of 70-90%. The second stage infrared-assisted air impingement drying also had temperatures 65-85 °C. The drying kinetics (effective moisture diffusivity (), Biot number (), and mass transfer coefficient () were studied via the product qualities (broken ratio, firmness, microstructure, and water-soluble polysaccharide content) and specific energy consumption (SEC) of the drying processes. The results showed that two-stage drying led to the lowest drying time and energy consumption, and also obtained the best qualities. Box-Behnken experimental design with response surface methodology (RSM) was used to optimize the two-stage operating conditions as 82 °C under vacuum drying until a moisture content of 81% and a temperature of 69 °C with infrared-assisted air impingement drying was achieved. These findings suggested that two-stage vacuum and infrared-assisted air impingement drying is a promising method for producing high quality and energy efficient dried poria cubes.
本研究的目的是开发一种高效的茯苓块干燥技术，以提高产品质量。采用不同方法对茯苓块进行干燥，包括气流冲击干燥、红外辅助气流冲击干燥、真空干燥、两段真空干燥以及红外辅助气流冲击干燥。将结果与热风干燥的结果进行比较。对于两段干燥，测试条件为第一阶段真空干燥，温度在65 - 85°C之间，转换含水率为70 - 90%。第二阶段红外辅助气流冲击干燥温度也为65 - 85°C。通过干燥过程的产品质量（破碎率、硬度、微观结构和水溶性多糖含量）和比能耗（SEC）研究干燥动力学（有效水分扩散系数（）、毕渥数（）和传质系数（））。结果表明，两段干燥导致最短的干燥时间和能耗，并且还获得了最佳质量。采用响应面法（RSM）的Box - Behnken实验设计将两段操作条件优化为真空干燥82°C直至含水率达到81%，然后红外辅助气流冲击干燥温度为69°C。这些发现表明，两段真空和红外辅助气流冲击干燥是生产高质量和高能效干燥茯苓块的一种有前景的方法。
