Detection of Water Content in Rapeseed Leaves Using Terahertz Spectroscopy

Abstract

The terahertz (THz) spectra of rapeseed leaves with different water content (WC) were investigated. The transmission and absorption spectra in the range of 0.3–2 THz were measured by using THz time-domain spectroscopy. The mean transmittance and absorption coefficients were applied to analyze the change regulation of WC. In addition, the Savitzky-Golay method was performed to preprocess the spectra. Then, the partial least squares (PLS), kernel PLS (KPLS), and Boosting-PLS were conducted to establish models for predicting WC based on the processed transmission and absorption spectra. Reliable results were obtained by these three methods. KPLS generated the best prediction accuracy of WC. The prediction coefficient correlation (Rval) and root mean square error (RMSEP) of KPLS based on transmission were Rval = 0.8508, RMSEP = 0.1015, and that based on absorption were Rval = 0.8574, RMSEP = 0.1009. Results demonstrated that THz spectroscopy combined with modeling methods provided an efficient and feasible technique for detecting plant physiological information.

Molecular Characterization and Theoretical Calculation of Plant Growth Regulators Based on Terahertz Time-Domain Spectroscopy

“…As an advanced technology, terahertz (THz) has received more and more attention in the field of biological sciences [17][18][19]. It has unique absorption characteristics for heterogeneous and biological macromolecules.…”

Characterization and Water Content Estimation Method of Living Plant Leaves Using Terahertz Waves

“…This clearly indicated that Weight (g) the moisture in leaves evaporated more rapidly on the day 1 and 2 compared to day 3 and 4, thereby creating more air cavities in the leaves. To assess the variation of leaf WC during the leaf's water evaporation process, the measurements were translated into WC using [17,32],…”

“…Over the years, significant amount of contributions have been made [9][10][11][12][13], that address estimating the leaf's WC. There are techniques that offer high reliability yet they are inappropriate for long-term studies of the same plant leaves because of validity of measurements cannot be guaranteed [11,[14][15][16][17].…”

A Comprehensive Review on Food Applications of Terahertz Spectroscopy and Imaging

“…THz applications include security screening (García‐rial et al., ; Kaltenecker et al., ; (Liu, Zhong, Karpowicz, Chen, & Zhang, ), astronomical studies (Leisawitz et al., ), communication (Akyildiz, Miquel, & Han, ; Ergün & Sönmez, , nondestructive testing (Probst, Scheller, & Koch, ; Rutz, Koch, Khare, & Moneke, ), medical imaging (Bowman et al., ; Chavez, Bowman, Wu, Bailey, & El‐Shenawee, ; Dougherty et al., ; Fitzgerald et al., ; Sun et al., ; Truong, Fitzgerald, Fan, & Wallace, ), imaging of dental caries (Karagoz, Altan, & Kamburoglu, ; Ripoche, Reynard, Narcisse, & Roberts, ), pharmaceuticals (Markl, Dong, Li, & Zeitler, ; Pei et al., ; Sibik & Zeitler, ; Warnecke et al., , agricultural products (Liu et al., ; Liu, Liu, Hu, Yang, & Zheng, ; Luo, Zhu, Xu, & Cui, ; Nie, Qu, Lin, Dong, & He, ; Ogawa et al., ; Qin, Li, Chen, & Chen, ), food inspection and quality control (Ge, Jiang, Lian, & Zhang, ; Huang et al., , Shin, Choi, & Ok, ; Ok, Park, Kim, Chun, & Choi, ; Ok, Park, Lim, Jang, & Choi, ; Wang, Sun, & Pu, ; Yan, Liu, Qu, & Liu, ), environmental monitoring (Bigourd et al., ), and biosensing and label‐free monitoring of various biological processes (Yang et al., ). Full body THz scanners are installed in many airport checkpoints for detection of concealed objects and explosives.…”

“…. Narcisse, & Roberts, 2018), pharmaceuticals (Markl, Dong, Li, & Zeitler, 2018;Pei et al, 2018;Sibik & Zeitler, 2015;Warnecke et al, 2019, agricultural products (Liu et al, 2018Liu, Liu, Hu, Yang, & Zheng, 2016;Luo, Zhu, Xu, & Cui, 2019;Nie, Qu, Lin, Dong, & He, 2017;Ogawa et al, 2006;, food inspection and quality control Huang et al, 2015, Shin, Choi, & Ok, 2018Ok, Park, Kim, Chun, & Choi, 2014;Ok, Park, Lim, Jang, & Choi, 2018;Wang, Sun, & Pu, 2017;Yan, Liu, Qu, & Liu, 2018), environmental monitoring (Bigourd et al, 2006), and biosensing and label-free monitoring of various biological processes . Full body THz scanners are installed in many airport checkpoints for detection of concealed objects and explosives.…”