Near infrared spectroscopy (NIRS) has been used as a valuable tool for quality control in the food
industry. The aim of the present study was to investigate the possibility of developing a NIRS calibration
for gluten determination in flour and batter, suitable for the analysis of gluten-free food products.
Reflectance data was used for calibration based on modified partial least squares (MPLS) regression.
Independent prediction equations were developed for flour and for batter. Spectral models using mean
spectra of two scans (average spectra), were compared with those using the two individual spectral data.
The best model obtained for flour was using the average spectral data (R2 ¼ 0.985; r2 ¼ 0.967) and for
batter samples was using the individual spectral data (R2 ¼ 0.926; r2 ¼ 0.825). It is concluded that the
application of NIRS methodology can predict accurately the concentration of gluten content in flours and
batters, but it should not be considered as a reliable method for determining gluten contamination in
gluten-free products.