In-Stream Measurement of Canola (Brassica Napus L.) Seed Oil Concentration Using in-line near Infrared Reflectance Spectroscopy

Abstract

Natural variation in the seed oil concentration of oilseed crops sent to a crushing plant can impair the recovery of the oil from the seed. Consequently, there is interest in applying in-line near infrared (NIR) spectroscopy to measure the oil concentration of the seed to be processed and, in using the information obtained, to maximise expeller efficiency. The objective of this study was to determine how well in-line NIR spectroscopy could determine the seed oil concentration of canola ( Brassica napus L.) when there was direct contact of the sensor head with the grain stream. Reflectance spectra from 850 nm to 1650 nm were obtained by sliding grain samples of canola directly across the sensor head of the Polytec 1721 NIR reflectance analyser. Reference analytical results were estimated using the NIR optical spectra as regression estimators. The resulting prediction equation with eight latent variables resulted in a coefficient of determination of 0.95, standard error of cross-validation of 0.727% and relative performance determination of 4.77. Validation results, based on site or year omission, confirmed the ability of the instrument to accurately predict seed oil concentration in a grain stream. This creates opportunities for monitoring the oil content of seed entering the expeller and using this information to adjust the expeller for maximum efficiency.