Prediction for mixture rate of buckwheat flour against wheat flour using Excitation-Emission matrix (EEM)

Abstract

Excitation-Emission matrix (EEM) fluorescence spectroscopy was applied to estimate the mixture rate of the buckwheat flour and the wheat flour. Eleven kinds of mixture of the buckwheat flour and the wheat flour were measured by EEM with excitation wavelength range of 200-900 nm and emission wavelength range of 200-900 nm. PLS regression analysis was applied to the EEM data obtained from the above measurement and the prediction formula was calculated using seven latent vectors. Coefficient of the prediction formula showed that significant EEM data was contained in the excitation wavelength range of 340-555 nm and emission wavelength range of 500-755 nm. PLS regression analysis was again applied to the EEM data of the above limited wavelength area. The accuracy of the standard curve did not change significantly from the result when the range of the wavelength was not limited. Measurement time was reduced from 515 seconds to 105 seconds per each sample. EEM measurement is an applicable method to detect the mixture rate of buckwheat and wheat flours easily and rapidly.