Variation in Glucosinolates in Oriental Brassica Vegetables

Abstract

The glucosinolates (GSs) were estimated in the normally eaten portions of 72 cultivars of Oriental brassica vegetables including mustard greens ( Brassica juncea L.), Chinese kale ( B. oleracea L. Alboglabra Group Bail.), Chinese cabbage ( B. rapa L. Pekinensis Group Bail.), pak choy ( B. rapa Chinensis Group Bail.), tendergreen ( B. rapa Perviridis Group Bail.), turnip ( B. rapa L. Rapifera Group Bail., B. narinosa Bail., and B. nipposinica Bail.). Variation in GS profiles was complex. There was variation in percentages of major GSs and total GS among B. juncea, B. oleracea , and the combination B. rapa plus narinosa and nipposinica and among four subspecific groups of rapa plus the two species closely related to rapa: narinosa and nipposinica. B. juncea had distinctively high proportions of allyl-GS, ranging from 81% to 94%, whereas B. oleracea had distinctively high proportions of 4-methylsulfinylbutyl-GS, ranging from 9% to 68%. Differences in GS profiles among the rapa groups, narinosa and nipposinica , were less distinctive. Cultivars of pak choy from China differed in percentages of three minor GSs from cultivars from Japan and elsewhere. There was also variation among cultivars of Chinese kale and between turnip foliage and roots.