Fluorescence spectroscopy and Multivariate Analysis for the assessment of stability of the cereal flours during storage and thermal processing

Abstract

In this work, we used Fluorescence spectroscopy in combination with the Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) algorithm for the assessment of stability of the cereal flours, based on stability of their individual fluorescence components, which can be altered by shelf life or heating. The tested samples were commercial maize flour (Maize flour for human consumption),wheat (T-500) and graham flour, purchased directly from a local market. The fluorescence emission spectra of the flour samples were measured in the range of 280 nm to 660 nm with excitation wavelength varing from 250 nm to 360 nm in 10-nm steps. Resulting from the analysis, the four flourescence components were derived from the emission spectra of every analyzed sample. Our results showed that the components' positions were unchanged for all flours after 2 months storage, whereas for the samples with thermal processing at 180 °C during 1 h, the positions were shifted. This method may be useful and simple for screening of a large number of flour samples.