Prediction of the ash content of wheat flours using spectral and chemometric methods

Fourier transform infrared (FTIR) spectroscopy has been considered an important method in evaluating structural properties of biomolecules. The assignment of the spectra indicated combination bands of the chemical bonds (O–H, C–H, C–C, etc.) that compose the chemical constituents of biomass. This paper presents, for several regional common wheat varieties (Triticum aestivum L.): Crina, Dropia, Flamura, Gruia, Haiduc and wheat from Vaslui area, the comparative analyses of the infrared absorption spectra for two spectral ranges: near-infrared (NIR) region, in the corresponding wavelength of 700-1000 nm, and middle-infrared (MIR) region, in the corresponding wavenumber 600-1600 cm-1. The positions of the characteristic absorption peaks were observed at 877.49 and 941.03 nm in NIR region and 756.50, 857.86, 929.75, 999.83, 1076.34, 1150.08, 1244.92, 1336.95, 1415.46 and 1538.35 cm-1 in MIR region. The information obtained from the analysis of NIR-MIR spectra is used to rapidly determine some of physicochemical parameters of the wheat species-specific part. The aim of this study is to apply FT-NIR and FT-MIR spectroscopy to correlate those signals by the StatCorr analyze. A fast technique such as chemometric analysis on the basis of NIR and MIR spectra was used to predict the amount of ash from the flour sample. R square of prediction model is 0.7 and Root Mean Square Error of Prediction (RMSEP) using two Principal Component PCs is 1.5 % which certifies the calibration model.