Prediction of the amino acid composition in brown rice using different sample status by near-infrared reflectance spectroscopy

In this study, 279 samples of brown rice grains and their flour, selected from a larger original population, were scanned by NIRSystem model 5000 mono-chromator in these two kinds of sample status for near-infrared reflectance spectroscopy (NIRS) analysis. Spectral pretreatment method 2,8,8,1 combined with SNV + D scatter correction was found suitable for developing calibration equations for amino acids. Equations for total amino acid content and for all individual amino acids, excluding cystine, methionine and tyrosine, were developed with this spectral pretreatment method. These equations had low SECV (0.010–0.063%) and SEP (0.011–0.066%); with high 1 − VR (0.878–0.960), R² (0.837–0.947) and SD/SEP (2.421–4.333). The results suggest that equations for the thirteen amino acids from the two sample categories can be directly used to estimate the amino acid composition in brown rice. This indicates once more that NIRS is a powerful technology that could be very useful for the determination of amino acid content in breeding programs that involve brown rice as well as for quality control in the food industry.