Application of NIR spectroscopy to determine the basic biochemical parameters of black oat grain quality

Background. The purpose of this work was to develop calibration models for rapid assessment of the main biochemical parameters of grain quality of naked and covered black oat (Avena strigosa Schreb.) using near-infrared reflectance (NIR) spectroscopy. The use of whole oat grains makes it possible to preserve breeding material of special value, which is very important for breeders. Materials and methods. Black oat grain from 50 accessions from the VIR collection was grown in 2014–2020 in various agro-ecological conditions of the Russian Federation. Chemical parameter values for constructing calibration models were determined in the Laboratory of Biochemistry and Molecular Biology of VIR using traditional methods, such as Kjeldahl for protein/nitrogen, Soxhlet extraction (modified by S.V. Rushkovsky) for oil, polarimetry according to Evers for starch, and gravimetry for beta-glucans. Results. The work resulted in the construction of calibration models for the determination of protein, oil, starch and beta-glucans in whole grains of black oat by a Bruker's MATRIX-I IR analyzer (Germany). A test batch of 20 accessions was used for assessing reliability of the constructed models. The models for determining protein, starch and oil were found to be reliable, while the model for determining beta-glucans needs improvements. It was found that the difference between the values obtained by spectroscopy and by standard chemical methods averaged 0.38 % for protein, 0.57 % for starch and 0.30 % for oil, which does not exceed the maximum permissible error of parallel measurements. The relative difference between the studied indicators does not exceed 3-6 % on an average. Conclusion. The proposed physical method for the analysis of black oat grain allows an express preliminary assessment of breeding material with a high speed of analysis. The main advantages of the method include the possibility of preserving valuable starting material, economizing on reagents, increasing labor efficiency, and obtaining data simultaneously on several parameters of the scanned sample with a specified repeatability.