农业机械学报2017，Vol.48Issue(6)：302-311,10.DOI:10.6041/j.issn.1000-1298.2017.06.040
直流高压电场中枸杞的干燥特性与数学模型研究
Drying Characteristics and Mathematical Models of Chinese Wolfberry in DC High Voltage Electric Field
摘要
Abstract
Aiming to explore the new drying technology of Chinese wolfberry,improve the quality of dried Chinese wolfberry,and find suitable mathematical model,the drying experiments were carried out for Chinese wolfberry fruits with a multiple needle-to-plate electrode at 0 kV,22 kV,28 kV,34 kV,40 kV and 45 kV at the same temperature and humidity in DC high voltage electric field.The shrinkage rate,rehydration rate,polysaccharides and vitamin C content of the dried wolfberry fruits were measured.The mass transfer enhancement factor,the effective moisture diffusion coefficient (Deff) and the specific energy consumption were also calculated.Ten mathematical models were then applied to simulate drying curves based on three statistical parameters.The results showed that the drying rate of Chinese wolfberry fruits in the DC high voltage electric field was higher than that of the control.Under the same voltage,the drying rate of the Chinese wolfberry was gradually changed with the prolonging of drying time.The drying rate and specific energy consumption were increased with the increase of voltage.By ANOVA,the results showed that Chinese wolfberry fruits in the DC high voltage electric field had a significant effect on rehydration rate compared with control (p ＜ 0.05),but there were no significant differences in shrinkage rate of dried Chinese wolfberry fruits (p ＞0.05).DC high voltage electric field drying could keep more polysaccharides and vitamin C content compared with oven drying.The mass transfer enhancement factor was heightened with the increase of voltage,and the effective moisture diffusion coefficient (Deff) values were increased with the increase of voltage.It was clear that all ten mathematical models could satisfactorily describe drying curves of Chinese wolfberry fruits treated by DC high voltage electric field.From the statistical result,the Midill and Kucuk model was selected as the best model to represent the drying characteristics of Chinese wolfberry fruits in the DC high voltage electric field.Microstructure detection indicated that the microstructure of Chinese wolfberry fruits was changed in the DC high voltage electric field.Those results may provide some clues and practical guidance for optimizing the process of drying Chinese wolfberry fruits in DC high voltage electric field drying system,improving the drying efficiency and promoting the development of Chinese wolfberry fruits drying technology.关键词
枸杞/高压电场干燥/干燥速率/复水率/数学模型Key words
Chinese wolfberry fruits/high voltage electric field drying/drying rate/rehydration rate/mathematical models分类
农业科技引用本文复制引用
丁昌江,杨茂生..直流高压电场中枸杞的干燥特性与数学模型研究[J].农业机械学报,2017,48(6):302-311,10.基金项目
国家自然科学基金项目(51467015)和内蒙古工业大学基金项目(ZD201311) （51467015）
