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International Agrophysics
publisher:Institute of Agrophysics
Polish Academy of Sciences
Lublin, Poland
ISSN: 0236-8722

vol. 14, nr. 2 (2000)

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Estimation of minor components in caraway, fennel and carrots by nirs comparison of results from dispersive and fourier-transform instruments
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Schulz H., Quilitzsch R., Drews H.-H., Krüger H.
Federal Centre for Breeding Research on Cultivated Plants, Institute for Quality Analysis, Neuer Weg 22/23 D-06484 Quedlinburg, Germany

vol. 14 (2000), nr. 2, pp. 249-253
abstract The purpose of the present study is to compare the prediction accuracy of some secondary metabolites occurring in caraway, fennel and carrot, recorded with two different NIR spectrometers. Based on the recorded spectra and the chemically determined reference values, chemometrical analyses were performed using a partial least squares (PLS) or a modified PLS algorithm. Very good calibration statistics (SECV, R2) were obtained for the prediction of the essential oil content in caraway both with the dispersive spectrometer system (0.20, 0.93) and with the FT-IR instrument (0.19, 0.92). The results received for the essential oil content in two harvests of fennel (1996+1997) gave nearly the same accuracy: (0.47, 0.92) and (0.58, 0.91). Satisfactory calibration results were received for the NIRS determination of total carotenoids in two harvests of carrots (1997: 3.54, 0.82 /1998: 3.45, 0.91) by using a FT-IR spectrometer. Applicable calibration results were received for total sugars in carrots (1997: 1.61, 0.67/1998: 1.14, 0.73).
keywords near-infrared spectroscopy, non-destructive measurements, caraway, fennel, carrot