基于近红外光谱法建立了快速预测烟用料液中水溶性总糖和还原糖含量的模型,用以评价烟用料液配制质量的稳定性。以连续流动法为参比,测定5个不同品牌120个料液样品中总糖和还原糖的含量;以近红外光谱仪分析样品,采用二阶导数和Norris滤波平滑对原始近红外光谱进行预处理,在5 400~7 600 cm^-1和4 000~4 600 cm^-1波段内用偏最小二乘法建立总糖和还原糖的定量分析模型。结果显示:当主因子数为6时,总糖定量分析模型的校正相关系数(R_c)为0.998 5、预测相关系数(R_p)为0.998 1、交互验证相关系数(R_cv)为0.998 8、校正均方根误差(RMSEC)为0.257、预测均方根误差(RMSEP)为0.261、交互验证均方根误差(RMSECV)为0.284;还原糖定量分析模型的R_c为0.999 0、R_p为0.998 7、R_cv为0.999 2、RMSEC为0.235、RMSEP为0.250、RMSECV为0.266。经配对T检验统计学分析,本法与连续流动法对料液样品中水溶性糖含量的测定不存在显著性差异。利用建立的模型对112个待检烟用料液样品中水溶性糖含量进行预测,运用统计过程控制技术中的3σ过程控制原理判断待检烟用料液配制质量的稳定性,并根据样品的理化指标来验证结果的准确度。结果表明,A品牌5,14,28号样品和C品牌21号样品均不属于正常样品,B、D和E品牌样品中水溶性糖含量均在质量控制范围内,说明样品配制质量的稳定性较好。

In order to evaluate the stability of the preparation quality of tobacco casings, models for the rapid prediction of water-soluble total sugar and reducing sugar in tobacco casings were established based on near infrared spectrometry. Continuous flow method was used as reference, the total sugar and reducing sugar in 120 tobacco casing samples from 5 different brands were determined. The samples were analyzed with near infrared spectrometer, and the original spectra were preprocessed with second derivative and Norris filtering smoothing. The quantitative analysis models for total sugar and reducing sugar were established by using partial least square method in the spectral ranges of 5 400-7 600 cm^-1 and 4 000-4 600 cm^-1. It was shown that when the number of principal factor was 6, the correlation coefficients of calibration (R_c), prediction (R_p) and cross validation (R_cv) for total sugar in the quantitative analysis model were 0.998 5, 0.998 1 and 0.998 8, respectively, and the root mean square errors of calibration (RMSEC), prediction (RMSEP) and cross validation (RMSECV) were 0.257, 0.261, and 0.284, repectively; R_c was 0.999 0, with R_p of 0.998 7, R_cv of 0.999 2, RMSEC of 0.235, RMSEP of 0.250, RMSECV of 0.266 for reducing sugar in the quantitative analysis model. Though paired T-test statistical analysis, there was no significant difference between continuous flow method and this method in the determination of water-soluble sugars in tobacco casings. The contents of water-soluble sugars in 112 test tobacco casing samples were predicted with the established models. The stability of the preparation quality of test tobacco casings were estimated by the 3σ process control principle of statistical process control technology, and the accuracy of results was verified according to the physical and chemical indexes of the samples. The results showed that No. 5, 14, 28 samples from brand A and No. 21 sample from brand C were unnormal, and the contents of water-soluble sugars in brand B, D and E were all within the quality control ranges, indicating that the quality of sample preparation was stable.