食品工业科技2017，Vol.38Issue(5)：114-119,6.DOI:10.13386/j.issn1002-0306.2017.05.013
稻谷低温低湿干燥特性与水分迁移分析
Analysis of drying characteristics and moisture migration for paddy rice under low temperatures and low relative humidities
摘要
Abstract
The thin-layer drying experiments of paddy rice with different initial moisture contents (18.9％ ～29.6％)were conducted under low temperatures and low relative humidities.Mathematical models,drying duration and effective moisture diffusivity were used to investigate the effects of initial moisture content,drying temperature and air relative humidity on the external moisture diffusion characteristics of paddy rice.LF-NMR was adopted to analyze the internal moisture dynamic of kernels during the drying process of paddy rice.The results showed that the lower drying temperature,the more significantly humidification could shorten the durations of paddy rice.The Page model could fit the drying curves of paddy rice very well,and the mathematical expressions for parameters k and n could be better described by the experimental variables.Besides,the effective moisture diffusivity of paddy rice was high significantly(p ＜ 0.01)influenced by MC0,T and RH,and Deff varied from 3.0697 × 10-10 m2/s to 5.0369 × 10-10 m2/s.During the whole drying process of paddy rice,the data of LF-NMR indicated that both the A21 peak area representing for " bound water" and A22 peak area representing for capillary water decreased significantly,while the A23 peak area representing for free water kept steady.When the moisture content of paddy rice was decreased to 14.5 ％ ～ 16.5 ％,the LF-NMR signal peak of capillary water disappeared.We can combine the continuous weighing method and LF-NMR technology to effectively analyze the laws of moisture diffusion and moisture state transformation during the low-temperature and low-relative humidity drying process of paddy rice.关键词
稻谷/低温低湿/干燥特性/有效水分扩散系数/核磁共振Key words
paddy rice/low temperature and low relative humidity/drying characteristics/effective moisture diffusivity/nuclear magnetic resonance分类
轻工纺织引用本文复制引用
汪楠,邵小龙,时小转,沈飞,宋伟..稻谷低温低湿干燥特性与水分迁移分析[J].食品工业科技,2017,38(5):114-119,6.基金项目
公益性行业(粮食)科研专项(201513002-05) （粮食）
国家自然科学基金项目(31201443) （31201443）
江苏高校优势学科建设工程资助项目(PAPD). （PAPD）
