Variation and Distribution of Glucosinolates in 42 Cultivars of Brassica oleracea Vegetable Crops

Brassica vegetables are known to contain glucosinolates that are precursors for bioactive compounds like isothiocyanates that have been shown to play an important role in human health. This study reports the results of a screening of 11 Brassica oleracea crops consisting of 42 cultivars (6 white cabbage, 5 red cabbage, 7 Brussels sprouts, 2 kale, 1 tronchuda, 3 oxheart cabbage, 2 kohlrabi, 6 broccoli, 5 cauliflower, 3 romanesco and 2 Savoy cabbage). All these cultivars were cultivated under the same conditions on a single location in the same season. The variation found in the level of glucosinolates is expected to be mainly due to the genetic variation. A large variation was observed in the level and profile of glucosinolates. Total glucosinolates varied from 14 to 625 µmol/100 g fresh weight. Glucoraphanin, the precursor of the isothiocyanate sulforophane, varied from 0 to 141 µmol/100 g fresh weight. Within broccoli glucoraphanin varied from 27 to 141 µmol/100 g fresh weight. Glucoiberin that is structurally related to glucoraphanin varied from 6 to 397 µmol/100 g fresh weight. Within broccoli glucoiberin varied from 21 to 397 µmol/100 g fresh weight