A common technological practice in Brussels sprouts (Brassica oleracea L. var. gemmifera) production is the removal of apical plant section a few weeks before harvest in order to promote the development of auxiliary buds (sprouts) and ensure higher yields. It is well-known that this measure positively influences the size of the sprouts, but until now no study has focused on the effect of decapitation on the content of primary and secondary metabolites in Brussels sprouts. Plants were decapitated one month before harvest, and sprouts were sampled from three sections along the stem (basal, middle, top) of each plant. The sprouts were harvested, weighed, and chemically analyzed. The content of individual sugars was assessed by HPLC and the content of individual phenolics and glucosinolates by HPLC-MS. Significant interactions between the decapitation and different stem sections were detected in the weight of the sprouts, as well as in their sugar levels. The highest sugar content was determined in basal sprouts collected from decapitated plants. Conversely, basal sprouts from nondecapitated plants were characterized by the lowest sugar content. No interaction between the decapitation and stem sections was detected in the level of phenolics or glucosinolates. Decapitation promoted the accumulation of all glucosinolates and hydroxycinnamic acids. Moreover, the content of glucosinolates and flavonoids was always highest in the sprouts from the top stem section.
Keywords: Brassica oleracea L. var. gemmifera; glucosinolates; phenolics; plant part; stem sections; sugars; top removal.