摘要
研究烟叶烘烤过程中水分相态变化,为烘烤工艺优化提供理论依据.以烤烟上部叶为材料,应用低场核磁共振技术对烘烤过程烟叶水分进行检测,经过1万次和10万次迭代分析,获取烟叶内部水分相态组成及信号幅值变化规律.结果表明:以10万次迭代反演所获取的结合水、半结合水和自由水3种相态表述烟叶叶片水分相态组成较优;烘烤过程中烟叶自由水信号幅值呈逐渐减小趋势,半结合水在38℃时明显增大,之后呈减小趋势,结合水在38℃时明显增大,42~45℃期间逐渐减小,48~54℃期间呈快速增大趋势;烘烤过程烟叶失水干燥表现为自由水流动性较大,首先从烟叶中脱除,半结合水通过转化为自由水散失,结合水不具有流动性,不易被干燥去除.低场核磁共振解析了烘烤过程烟叶水分相态变化规律,提供了一种快速精准检测烘烤过程烟叶中水分相态的方法.
In order to provide a theoretical basis for the optimization of curing process,moisture phase state of tobacco leaves during curing was studied.The upper leaves of flue-cured tobacco were used as the test material.The relaxation characteristics of tobacco leaves were detected during the curing process by the low-field nuclear magnetic resonance iterative optimization method to investigate the change of the components and content of moisture phase state in tobacco leaves by 10 thousand times and 100 thousand times of iteration analysis.The results showed that the bound water,the immobilized water and the free water obtained by the 100 thousand times of iteration gave a better description of the moisture phase state components of the tobacco leaves.The free water content of tobacco leaves steadily decreased during curing.The immobilized water increased significantly at 38 ℃,and then decreased.The bound water increased obviously at 38 ℃,decreased during the period of 42~45 ℃,and rapidly increased during the period of 48~54 ℃.In the process of dehydration of tobacco leaves during curing,free water,with larger mobility,was firstly removed from the tobacco leaves,then the immobilized water was lost through changing into free water,and the bound water was not easy to be removed for lack of liquidity.In conclusion,changes of moisture phase in tobacco leaves during the curing process were analyzed in this study with nuclear magnetic resonance,which provided a method for rapidly detecting the moisture phase of tobacco leaves during curing.
出处
《西南大学学报（自然科学版）》
CAS
CSCD
北大核心
2017年第12期12-17,共6页
Journal of Southwest University(Natural Science Edition)
基金
中国烟草总公司重庆市公司资助项目(NY20150601070011)
关键词
低场核磁
烟叶
烘烤
水分相态
low field nuclear magnetic resonance
tobacco leaf
flue-curing
moisture phase
作者简介
宋朝鹏（1978-），男，河南邓州人，副教授，博士，主要从事烟草调制与加工的研究．
