Inline simultaneous quantitation of tobacco chemical composition by infrared hyperspectral image associated with chemometrics

Rapid quantification of constituents in tobacco by NIR fiber‐optic probe

“…Figure 4 shows the correlation between the measured values (y measured) of the reference method and the results predicted (y predicted) by the PLS model (nitrate and ammonia) and siPLS (total alkaloids and reducing sugars). It was possible to obtain a good correlation for total alkaloids and reducing sugars models, and the values obtained for F I G U R E 4 Correlation between the measured values (y measured) of the reference method and the results predicted (y predicted) by the partial least-squares (PLS) model (nitrate and ammonia) and synergy interval PLS (siPLS) (total alkaloids and reducing sugars) coefficients (R 2 CV and R 2 p ) were higher than 0.9, which means an appropriate goodness-of-fit and fair precision. 4,39 For the other parameters, the models that were developed did not attain the recommended coefficient minimum values, obtained R 2 CV = 0.32 and R 2 CV = 0.77 for nitrate and ammonia, respectively.…”

“…For the PLS models, the spectra that range between 1,000 and 2,300 nm were used. Four datasets were created 1 for total alkaloids, 2 reducing sugars, 3 nitrate, and 4 ammonia with 245 samples. Each dataset was split into two new datasets (calibration and prediction) using the Kennard‐Stone algorithm 25 ; files were split into two thirds of the data for calibration and one third for prediction.…”

“…Change in the metabolites can modify the leaf characteristics and consequently affect the chemical composition and organoleptic characteristics in tobacco smoke 1–3 . There are several types of tobacco such as flue‐cured Virginia, 1,2 air‐cured Burley, 1,2 sun‐cured Oriental, 1 air‐cured Maryland, 1 and air‐cured Dark 4 . Among these, the main ones produced in Brazil are flue‐cured Virginia and air‐cured Burley 5,6 .…”

“…Among these, the main ones produced in Brazil are flue‐cured Virginia and air‐cured Burley 5,6 . Alkaloids, sugars, reducing sugars, nitrate, and nitrogen are some of the chemical components that are measured to determine the quality of these tobacco types 1,2,7 . Therefore, monitoring and controlling these components are significant quality control processes throughout batches and between years of production 3,4,8 …”

“…A large pool of methods and analytical techniques can be used to measure the constituents present in tobacco leaf. However, the International Organization for Standardization (ISO) recommends determining the routine chemical components such as total alkaloids, 9 reducing sugars, 10 and nitrate 11 by continuous‐flow analysis 2 . These traditional analytical methods are commonly executed in quality control laboratories.…”