Fast Determination of the Rubber Content in Taraxacum kok-saghyz Fresh Biomass Using Portable Near-Infrared Spectroscopy and Pyrolysis-Gas Chromatography

Taraxacum kok-saghyz (TKS) is a plant native to the Tianshan valley on the border between China and Kazakhstan. TKS rubber is a good substitute for natural rubber. TKS's breeding work necessitates the need to screen high-yielding varieties, hence rapid determination of rubber content is essential for the screening. Conventional analytical methods cannot meet actual needs in terms of real-time testing and economic cost. Near-infrared spectroscopy analysis technology, which has developed rapidly in the field of industrial process analysis in recent years, is a green detection technology with obvious merits of fast measurement speed, low cost and no sample loss. This research aims to develop a portable non-destructive near-infrared spectroscopic detection scheme to evaluate the content of natural rubber in TKS fresh roots. Pyrolysis gas chromatography (Py-GC) was chosen as the reference method for the development of NIR prediction model. 208 TKS fresh root samples were collected from the Inner Mongolia Autonomous Region of China. Near-infrared spectra were acquired for all samples. Randomly, two-thirds of them were selected as the calibration set, the remaining one-third as the validation set, and the partial least squares method was successfully established a good NIR prediction model for rubber content at 1080-1800 nm with a ratio of performance to deviation (RPD) of 5.54 and coefficient of determination (R-2) of 0.95. This study showed that portable near-infrared spectroscopy could be used with ease for large-scale screening of TKS plants in farmland, and could greatly facilitate TKS germplasm preservation, high-yield cultivation, environment-friendly, high-efficiency and low-cost rubber extraction, and comprehensive advancement of the natural rubber industry thereof.