Development of Fourier transform infrared spectroscopy in direct, non-destructive, and rapid determination of cotton fiber maturity

Abstract

Fourier transform infrared (FTIR) spectra of seed and lint cottons were collected to explore the potential for the discrimination of immature cottons from mature ones and also for the determination of actual cotton maturity. Spectral features of immature and mature cottons revealed large differences in the 900—1200 cm1 region, and such spectral distinctions formed the basis on which to develop a simple three-band ratio algorithm for classification analysis. Next, an additional formula was created to assess the degree of cotton fiber maturity by converting the three-band ratios into an appropriate FTIR maturity (MIR) index. Furthermore, the MIR index was compared with parameters derived from traditional image analysis (IA) and advanced fiber information system (AFIS) measurements. Results indicated strong correlations (R2 > 0.89) between MIR and M AFIS and between MIR and MIA among either International Cotton Calibration standards or selected cotton maturity references. On the other hand, low correlations between the pairs were observed among regular cotton fibers, which likely resulted from the heterogeneous distribution of structural, physical, and chemical characteristics in cotton fibers and subsequent different sampling specimens for individual and independent measurement.

Recent Progress in Fourier Transform Infrared (FTIR) Spectroscopy Study of Compositional, Structural and Physical Attributes of Developmental Cotton Fibers

“…This is because the microscopic procedure is subjective and depends on one’s judgment to assign the fibers into the appropriate class of either immature or mature fibers. On the ATR-FTIR spectral intensity differences between immature and mature fibers, Liu et al determined the key wavelengths first and then developed two simple algorithms ( R 1 and R 2 ) for their discrimination [16]. They observed that the R 1 values increase with R 2 values among a data set consisting of 402 seed bolls (Figure 2).…”

“…Plot of R 1 values vs. R 2 values from a total of 402 manually selected seed cottons (Reprinted with permission from [16]. Copyright 2011 SAGE).…”

Analysis of the physical properties of developing cotton fibres

“…Flowers were tagged as soon as they appeared, and harvested at the relevant dpa or days after flowering. Fibres from bolls at different developmental stages including green bolls that were 17,20,22,24,26,35,40,45,50, and 55 dpa and one boll that was matured and opened on the plant at 60 dpa were included. Bolls from 12 different plants were studied for all assays.…”

“…Cross-sections of cotton fibres were analysed to calculate cotton maturity ratio, an important fibre quality property that is directly related to the amount of cellulose deposited during the secondary wall biosynthesis [2,20]. Figure 5 shows TEM cross-sections of cotton fibres during biosynthesis.…”

“…Although determining is theoretically the most accurate approach of measuring fibre maturity, measurements are affected by significant experimental error because of fibre preparation and the limited number of fibres that can be 4 practically measured [15]. Some studies on measuring the development of cotton cell-wall thickening have been reported using different techniques: cross-section image analysis [14,16,17]; scanning probe microscopy (SPM) [11]; scanning electron microscopy (SEM) [18]; X-ray fluorescence spectroscopy (XRF) [19]; Fourier-transform infrared spectroscopy (FT-IR) [20]; and Goldthwait's method using a combination of two dyes, C.I. Direct Red 81 and C.I.…”