Glucosinolates from flower buds of Portuguese Brassica crops

Samples of green flower buds from Portuguese cabbage (Brassica oleracea var. tronchuda) and Portuguese kale (B. oleracea var. acephala) and B. rapa var. rapa were obtained from a local market and analysed for individual and total glucosinolate composition. In the B. oleracea types, the major glucosinolates were 2-propenyl-, 3-methylsulphinylpropyl- and indol-3-ylmethyl-, which accounted for an average of 35, 25 and 29%, respectively, of the total glucosinolate content, while in B. rapa, but-3-enyl- represented 86% of the total, with pent-4-enyl and 2-phenylethyl- being the other major glucosinolates. The average total glucosinolate content of the flower buds was between 2518 mu mol 100 g(-1) dry wt in Troncha (B. oleracea var. tronchuda) and 4979 mu mol 100 g(-1) dry wt in Nabo (B. rapa), which is much higher than the highest amounts reported for broccoli (B. oleracea var. italica), the florets of which are harvested at a similar stage in the plant's development. Copyright (C) 1997 Elsevier Science Ltd.