Fatty Acid Determination in Oilseeds with FT-NIR Spectroscopy
Dagmar Behmer, Bruker Optik GmbH 
Ettlingen, Germany
 
The quality of edible oil is highly correlating with the fatty acid composition of its corresponding seeds. For sunflower seeds, the amount of Oleic acid is an important parameter to monitor. Over the last decade, there has been an increased interest in breeding sunflower seeds with high Oleic acid content (>80%). This type of breed is high in mono-saturates and therefore associated with a healthy diet. Rape seed breeders can obtain valuable additional information like fatty acids, including Erucic acid as well as the Glucosinolate content, crucial parameters for the palatability of the finished product. 

In the following study, FT(Fourier Transform)-NIR in reflection was utilized to rapidly analyze the fatty acid concentrations present in sunflower and rape seeds. Absorbance spectra were collected in the wavelength range from 12,500cm-1 to 3,600cm-1 (800 - 2780nm) using a Bruker MPA FT-NIR spectrometer. Partial Least Square (PLS) analysis was performed on the data set, and calibrations were developed for prediction of the various fatty acid concentrations and Glucisinolate in rape seed. The optimum model was chosen based on the Coefficient of Determination (R2), Root Mean Square Error of Prediction (RMSEP) and Ratio of Performance to Deviation (RPD). 

All developed calibrations yielded R2 values >90 and RPD >3, indicating the suitability of FT-NIR analysis for fatty acid determination in oil seeds.