Raps im ökologischen Landbau – Qualitätsbewertung mit Hilfe der Nah-Infrarot-Spektroskopie (NIRS)

Summary

The demand for organic oil seed rape is very high. The reason is, rape oil plays an important role in human nutrition and rape cake in animal nutrition. The range of varia-tion in the quality of oil seed rape required a fast and easy analytical method for the determination of the main ingredients. Near-infrared spectroscopy (NIRS) is known for its rapidity and accuracy and may become a useful tool in predicting the quality of organic growing oil seed rape. The aim of the investigations was to evaluate the ability of NIRS to predict the content of oil and fatty acids in full fat oil seed rape without any preparation. Spectra from 125 rape samples were scanned in the spectral range from 1000 to 2500 nm and used to develop NIRS equations. Two-third of the samples were used in the calibration set and the remaining samples in the validation set. NIRS equations were calculated by partial least square regression and different pretreat-ments of spectra. Prediction was successful for oil content (r=0.97) with an standard error of prediction of 0.42. The fatty acids were also successfully predicted with re-gression coefficients from 0.86 to 0.97 with exception of the erucic acid. But the con-tent of erucic acid is quite low, the prediction of the content was not satisfying.
The obtained results indicated that the NIRS could be successful used in the predic-tion of ingredients in oil seed rape without sample preparation and therefore for the fast assessment of product quality in oil seed rape.