Calibration of NMR Spectroscopy for Accurate Estimation of Oil Content in Sunflower, Safflower and Castor Seeds

Oil content analysis in oilseed crops requires methods that are non-destructive, accurate, fast, eco-friendly (without the use of solvent), inexpensive in terms of consumables, and easy to use. Pulsed low-resolution nuclear magnetic resonance (NMR) satisfies all these conditions. The objective of the present study was to develop an oil measurement method for seeds using NMR spectrometry. A bench-top pulsed NMR analyser was calibrated with respect to temperature. Six genotypes each of sunflower, safflower and castor were used for the analysis. Changes in sample conditioning temperature can lead to significant changes in the calibration graph. Based on the statistical parameters (correlation coefficient, variance and standard deviation) obtained, the best calibration was found for sunflower and safflower at 40°C and castor at 44°C among the temperature ranges tested.