谷物平衡水分研究概况

控制吸湿是谷物安全贮藏的基本原则之一,平衡水分测定可用来判断谷物水分变化的趋向.概述了谷物平衡水分测定的原理及数学模型分析,并归纳,发生纳滞后效应的可能理论、影响谷物吸着(包括吸附与解吸)等温线测定的因子,还重点介绍了近年发展起来的、利用平衡水分吸附/解吸数据分析谷物及食品的热动力学函数--水分吸着等热.这些研究进展对完善我国储粮生态区域划分、谷物主产区低温干燥、设计干燥程序和设备、谷物及加工产品的包装及货架期皆有意义.

Progress of Research on Grain Equilibrium Moisture

Preventing moisture absorption by grains is one of the principles for grain safe storage,and the measurement of equilibrium moisture content (EMC) is a way to estimate whether the grains will absorb or desorb moisture.The methods for EMC measurement of grains are summarized and discussed with regard to the circumstance in which moisture measurement is required.Refining the predictive equations available for the relationship between moisture content and relative humidity at equilibrium is a timely contribution for improving physical control in storage.The theory for moisture hysteresis of sorption is also introduced.The thermodynamics function such as isosteric heat of sorption of water has recently been studied from EMC isotherm of grains and food.This review on EMC and its isotherm equations and thermodynamics function for grains is helpful to accurately divide the ecological region for grain storage in China,to decide grain drying in low temperature sect,and to design drying program,equipments,packaging and shelf life of grains and their processed products.