Comparison of the usability of different spectral ranges within the near ultraviolet, visible and near infrared ranges (UV-VIS-NIR) region for the determination of the content of scab-damaged component in blended samples of ground wheat

Abstract

Soft wheat grain samples of the same variety were obtained from a plot where the crop grew under natural conditions (control material) and from a plot where the crop was inoculated with Fusarium culmorum. The grain was ground and sieved with the finest fraction (a particle size less than 0.18 mm) of both materials being used for the preparation of samples in which the content of damaged constituent varied from zero to approximately 84%. Diffuse reflectance spectra of the absorbance from the blended samples were recorded in the 200-2500 nm spectral range and multivariate calibration PLS (Partial Least Squares) models were built within three spectral ranges: 200-2500, 200-1400 and 1400-2500 nm. Before modelling, several variants for spectra pre-processing were tried: multiple scatter correction, single and double differentiation, in all cases with and without centring. Single differentiation followed by centring was found to be the best method for spectra pre-processing in all spectral ranges. Very good calibration models were obtained for the whole and shorter wavelengths spectral ranges, allowing the detection of 1.50 and 0.76% of the content of scab-damaged constituent, respectively. Two-dimensional correlation spectroscopy applied to the set of spectra enabled the assignment of spectral bands and an analysis of changes in the chemical composition caused by scab damage. It was found that the content of protein and lipids increased with an increase of the scab-damaged constituent, whereas the content of moisture and starch decreased.

Effect of particle size and spectral sub-range within the UV-VIS-NIR range using diffuse reflectance spectra on multivariate models in evaluating the severity of fusariosis in ground wheat

“…As regards the improvement of the models observed when the UV range is included in modelling, this finding is in line with our previous results obtained for fine fraction only and a lower number of cultivars (Siuda et al 2006;2008). Therefore, considering the results presented here, there now exists better evidence to suggest that improved results can be obtained from the UV sub-range than from the two other sub-ranges considered.…”

“…Another approach that can be useful in the detection of scab/DON damaged grain is based on optical measurements of ground grain followed with multivariate calibration (Abramović et al 2007, Kos et al 2002, 2003, Siuda et al 2006, 2008. Errors of calibration models are a key question in such an approach as they determine the ability of the method to detect fusariosis.…”

“…Errors of calibration models are a key question in such an approach as they determine the ability of the method to detect fusariosis. Our previous papers (Siuda et al 2006(Siuda et al , 2008 showed that the most promising PLS models for the fine fraction (particle size less than 0.180 mm) of ground winter wheat were the models based on spectra recorded within the UV range, or when the measurement covered additionally the VIS range. Errors of these models when applied to DON content resulted in a limit of detection below 1 ppm (Siuda et al 2008).…”

A Modified Approach to Evaluation of DON Content in Scab-Damaged Ground Wheat by Use of Diffuse Reflectance Spectroscopy

“…It has been shown in our previous paper (Siuda et al 2006) that the PLS1 calibration method applied to single differentiated spectra provided better results than other approaches we had tried. Therefore, only this approach to modeling was applied in the present work.…”

Application of ATR-FTIR analysis for determination of fumonisins in corn

“…Apart from the methods of the mid-infrared spectrum, detection of fungi and prediction of mycotoxin contamination were frequently performed using NIR spectroscopy. Measurements in near-infrared region proved appropriate for quantitative evaluation of visible changes in the kernel and estimation of the levels of DON (Dowell et al 1999;Delwiche, 2003;Delwiche and Hareland, 2004;Siuda et al 2006), fumonisin (Dowell et al 2002;Berardo et al 2005) and aflatoxin (Pearson et al 2004). The application of Fourier transform instruments (FT-NIR) has been showing increasing tendency because of a high signal-noise ratio, accuracy in wavelength defining, rapid spectral recording and high resolution (De Girolamo et al 2009;Gaspardo et al 2012;Della Riccia and Del Zotto, 2013).…”