Volatile Isothiocyanates and Nitriles from Glucosinolates in Rutabaga and Turnip1

Glucosinolates extracted from seeds of 2 rutabaga ( Brassica napus L. Napobrassica group) and 2 turnip ( B. rapa L. Rapifera group) cultivars, and also from roots sampled at 2-week intervals during growth and development on 2 soil types, were hydrolyzed and the individual volatile products identified by gas chromatography and mass spectrometry. Four isothiocyanates (3-butenyl-, 4-pentenyl-, 4-methylthiobutyl-, and 2-phenylethyl-isothiocyanates), and 2 nitriles (1-cyano-4-methylthiobutane and 2-phenylethylnitrile), were identified. Yields of each constituent varied considerably between cultivars, and also seasonally in root tissue, but generally were quantitatively similar in trend within cultivar grown on loam and organic soils; 2-phenylethyl-isothiocyanate was predominant in roots.