Application of near-infrared reflectance spectroscopy for the estimation of protein and L-canavanine contents in seeds of one-flowered vetch (Vicia articulata Hornem.)

Abstract

In this work it has been evaluated the effectiveness of near-infrared reflectance spectroscopy (NIRS) for the estimation of two constituents affecting the nutritional quality of the seeds of one-flowered vetch (Vicia articulata Hornem.): protein and L-canavanine, a toxic non-protein amino acid. The NIRS calibrations showed good statistics with coefficients of multiple determination (R2) of 0.97 for total protein and 0.95 for L-canavanine. The developed equations were further used to estimate the contents of protein and L-canavanine of a set of unknown samples (external validation). The equation for total protein was able to predict with an accuracy similar to that of the reference method showing a correlation (r2) between the reference and predicted values of 0.95. In the case of L-canavanine, r2 was only 0.72 and the equation was only effective to discriminate samples into groups of low, medium and high contents.