低场核磁共振法测定烘烤过程中烤烟主脉的水分  

Moisture content in midrib of tobacco leaves during flue-curing as determined by LF-NMR

作　　者：魏硕[1] 王德勋[2] 苏家恩[2] 李再光[2] 徐发华[2] 王新中[2] 何海萍[2] 余源[2] 宋朝鹏[1] 

机构地区：[1]河南农业大学烟草学院,郑州市文化路95号450002 [2]云南省烟草公司大理州公司,云南省大理市鹤庆路71号671000

出　　处：《烟草科技》2016年第10期31-35,共5页Tobacco Science & Technology

基　　金：中国烟草总公司云南省公司资助项目"返青寡日照等条件下难落黄烟叶的烘烤技术研究及推广"(2015YN20)

摘　　要：为了准确掌握烘烤过程中烟叶主脉水分变化情况,利用低场核磁共振法测定了烘烤过程中烤烟主脉含水率及水分状态,并与烘箱干燥法含水率检测结果进行对比分析。结果表明:(1)鲜烟叶及烘烤过程中烟叶主脉含有结合水T_(21)(1~10 ms)和自由水T_(22)(100~1 000 ms);随着烘烤进程的推进,自由水信号幅值M_(22)与水分总信号幅值M_(20)呈现降低趋势,结合水信号幅值M_(21)呈现先升高后降低趋势。(2)线性回归分析表明,反演谱曲线总信号幅值分别与主脉水分质量、干基含水率呈极显著线性正相关(决定系数分别为R^2=0.997 9,R^2=0.998 3,P<0.01),由回归方程可得到烘烤干燥过程中主脉含水率。(3)与烘箱法相比,低场核磁共振法检测结果稳定性较好,适用于烘烤过程中烟叶主脉含水率的快速、准确检测。In order to study the moisture variations in midrib of tobacco leaves during flue-curing, low-field nuclear magnetic resonance（LF-NMR） was used to determine the content and state of moisture, and the results were compared with those determined by a conventional oven method. The results showed that： 1） The moisture in midrib of fresh green tobacco leaves included bound water T_（21）（1-10 ms） and free water T_（22）（100-1 000 ms）.During flue-curing, the signal amplitude of free water M_（22） and total water M_（20） decreased, and the signal amplitude of bound water M_（21） increased first then decreased. 2） Linear regression analysis indicated that the total signal amplitude of inversion spectrum positively correlated to the moisture content and dry weight base moisture content at a significant degree（coefficient of determination R2=0.997 9, R2=0.998 3, P〈0.01）. The moisture content in leaves during flue-curing could be obtained by the regression equation obtained. 3）Comparing with the oven method, the stability of LF-NMR was better. LF-NMR is thus suitable for the rapid and accurate determination of moisture contents in midrib of tobacco leaves during flue-curing.

关 键 词：低场核磁共振 烤烟 烘烤 主脉 含水率 

分 类 号：TS441[农业科学—烟草工业]