On the feasibility of near-infrared spectroscopy for the identification of Nicotiana species
Stephanie Jaen, Sulaf Assi, Dhiya Al‐Jumeily, Luis Vargas Canelos, Rachel Leeson
Spectroscopy Letters June 3, 2026 DOI: 10.1080/00387010.2026.2676027 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational laboratory study Peer reviewed |
|---|---|
| Population | Three Nicotiana species (N. tabacum, N. glauca, N. rustica) and three handcrafted smokeless tobacco samples (Ecuadorian, Peruvian white, Peruvian brown) from Ecuador and Peru |
| Measures | Near-infrared (NIR) spectroscopy, correlation in wavenumber space (CWS), principal component analysis (PCA) |
| Key findings | Near-infrared spectra separated the three Nicotiana species and three smokeless tobacco products into distinct clusters, with spectral differences attributed to alkaloids, proteins, and moisture. The Ecuadorian product correlated closely with N. rustica and the Peruvian white product with N. glauca, while the Peruvian brown product did not correlate with any species. The authors state this is the first NIR spectral investigation of N. glauca and N. rustica and the first chemical characterization of these Achuar and Ashaninkas products. |
Abstract
This study evaluates the feasibility of near-infrared (NIR) spectroscopy for identifying biochemical differences in Nicotiana species (N. spp.) in ceremonial, handcrafted Indigenous smokeless tobacco products from Ecuador and Peru. NIR spectra of three N. spp. Nicotiana tabacum (N. tabacum), Nicotiana glauca (N. glauca), Nicotiana rustica, (N. rustica) and three smokeless tobacco samples (SLT), (Ecuadorian, Peruvian white and Peruvian brown) were collected. For each sample, more than 20 subsamples were taken. Spectra were exported to MATLAB 2024b, where multiplicative scatter correlation and first-derivative was applied prior to spectral analysis. Spectral analysis involved evaluating spectral quality, spectral interpretation, and applying correlation in wavenumber space (CWS) and principal component analysis (PCA). Spectral interpretation showed similar absorption bands in both wet (N. species) and dry (SLT) samples; however, dry samples showed stronger absorbance due to reduced interference from water. Bands corresponding to water showed absorbance around 4716 cm−1 in the wet samples. CWS applied to the NIR spectra showed close correlation between Ecuadorian sample and N. rustica and between Peruvian white and N. glauca. However, Peruvian brown sample did not correlate with any species. PCA showed distinct clusters for each of the N. species and the tobacco samples corresponding to biochemical differences in the samples. This is the first study to investigate the NIR spectral signatures of N. glauca and N. rustica, as previous studies have been limited to N. tabacum. In addition, this work provides the first chemical characterization of handcrafted shamanic tobacco produced by the Achuar Indigenous community in Ecuador and Ashaninkas in Peru. NIR spectral signatures showed key differences in alkaloids, proteins, and moisture bands. However, due to sampling limitations, future work will focus on evaluating the findings of the study with larger sample set.