GLUCOSINOLATES FROM FLOWER BUDS OF PORTUGUESE BRASSICA CROPS

Samples of green flower buds from Portuguese cabbage (Brassica olerace a var. tronchuda) and Portuguese kale (B. oleracea var. acephala) and B. rapa var. rapa were obtained from a local market and analysed for i ndividual and total glucosinolate composition. In the B. oleracea type s, the major glucosinolates were 2-propenyl-, 3-methylsulphinylpropyl- and indol-3-ylmethyl-, which accounted for an average of 35, 25 and 2 9%, respectively, of the total glucosinolate content, while in B. rapa , but-3-enyl- represented 86% of the total, with pent-4-enyl and 2-phe nylethyl- being the other major glucosinolates. The average total gluc osinolate 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 am ounts reported for broccoli (B. oleracea var. italica), the florets of which are harvested at a similar stage in the plant's development. Co pyright (C) 1997 Elsevier Science Ltd.