文献类型： 外文期刊

作者： Guo, Gao-fei ¹ ; Li, Bin ¹ ; Liu, Chao-xian ¹ ; Jin, Xin ² ; Wang, Zhao-gai ³ ; Ding, Mei-zhou ⁴ ; Chen, Liang-yuan ¹ ; Z ¹ ;

作者机构： 1.CNTC, Zhengzhou Tobacco Res Inst, Zhengzhou, Henan, Peoples R China

2.Soochow Univ, Suzhou, Peoples R China

3.Henan Acad Agr Sci, Inst Agr Prod Proc, Zhengzhou, Henan, Peoples R China

4.China Tobacco Henan Ind Co Ltd, Zhengzhou, Henan, Peoples R China

关键词： Fresh tobacco curing; Drying; Low-field nuclear magnetic resonance; TG-NMR; MRI

期刊名称：JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY （ 影响因子：4.626； 五年影响因子：3.458 ）

ISSN： 1388-6150

年卷期： 2019 年 135 卷 4 期

页码：

收录情况： SCI

摘要： Curing is an essential procedure in tobacco primary processing. The moisture mobility and diffusion characteristics during drying are the key factors that affect the curing condition optimization. In the present study, the thermogravimetric analysis (TG) was integrated to the online nuclear magnetic resonance analysis (NMR) to investigate the drying characteristics of fresh tobacco leaves (FTL) during hot air drying at 50 and 60 degrees C. The results of TG were used to analyze the drying kinetics and obtain the effective diffusion coefficient of moisture of FTL during drying. The moisture diffusion coefficient of FTL was 4.1782E-09m(2)s(-1) at 50 degrees C and 5.7777E-09m(2)s(-1) at 60 degrees C, respectively. The moisture mobility of the samples at different drying stages was monitored by the NMR analyzer. T-2 spectra showed that the initial ratios of semi-bound water and bound water in FTL were 93.2 and 6.8%, respectively. The drying rate showed a decreasing trend with the reduction in relaxation time of T-22 peak from about 80ms to about 30ms, especially for the ones dried at 60 degrees C. The reduced relaxation time of T-22 peak indicated that water activity in FTL was weakened during drying. Moisture distribution obtained by magnetic resonance imaging in FTL at different drying stages can reveal the moisture transfer path.