Volatile constituents throughout Brassica oleracea L. Var. acephala germination.

In this work, the volatile composition of kale ( Brassica oleracea L. var. acephala) and its variation during germination were monitored during the first 9 days of seedling development by headspace solid-phase microextraction (HS-SPME) combined with gas chromatography/ion trap-mass spectrometry (GC/IT-MS). Differences were found among the materials in the distinct analyzed periods. A total of 66 volatile compounds, distributed in several chemical classes, were determined: alcohols, carbonyl compounds (ketones, aldehydes, and esters), norisoprenoids, and terpenes, among others, sulfur compounds being the most abundant group in seeds and sprouts that exhibited allyl isothiocyanate as the major compound. Leaves of fully developed ground plant had the highest content of norisoprenoids, alcohols, and carbonyl compounds; in opposition, they showed lower levels of sulfur compounds, suggesting that these are important molecules for the development of kale, whereas the others are produced mainly during its growth.