Spectrophotometric Determination of Total Glucosinolate Content in Different Tissues of Camelina sativa (L.) Crantz

The objective of this study was to determine the total glucosinolate (GLS) content in Camelina sativa, using a simple and sensitive method, based on the colorimetric reaction of sodium tetrachloropalladate (II) with GLSs, and to quantify them by spectrophotometry without the use of HPLC. Glucosinolates from defatted meal, seeds, animal feeds and sprouts were extracted and isolated using a weak anion exchange column. Sodium tetrachloropalladate (II) solution was added to the extract and the absorbance measured at 420 nm. The repeatability (intra-assay) of the sodium tetrachloropalladate (II)—assay (Pd-assay) was very high, with CVs ranging from 2.07 to 0.90% for the single experiments. The inter-assay was also very high, displayed by a CV of 1.65% across all of the experiments. The Pd-assay is therefore able to quantify GLS amounts with good accuracy in all the tested matrices, which cover a very wide range from 0.50 µmol g⁻¹ DW in animal feed to about 40 µmol g⁻¹ DW in defatted meal. The good agreement between the Pd-assay and HPLC was testified by a significant correlation R² = 0.9937. These results indicate that the accuracy and repeatability of the Pd-assay are suitable for measuring total GLS in all camelina tissues tested.