Variation of major glucosinolates in different varieties and lines of rocket salad

Abstract

Glucosinolate (GSL) contents in five varieties and eleven lines of rocket salad (Eruca sativa L.) were quantified using HPLC-UV at 227 nm. Eleven GSLs including five aliphatic (glucoraphanin, glucothiobeinin, glucobrassicanapin, glucoerucin, and dimeric 4-mercaptobutyl GSL), two indolyl (glucobrassicin and 4-methoxyglucobrassicin), one aromatic (gluconasturtiin) and three unknown GSLs were identified based on our data base. Aliphatic GSLs were noted as the predominant group with an average 89% of the total content. The highest total GSL amounts were documented in ‘Herb-Fragrant Vegetable’ (31.12 μol·g⁻¹ dry weight (DW)), whereas the lowest was in line 28612 (9.91). Relatively 73% of lines among the lines documented the content more than 8 μmol·g⁻¹ DW of dimeric 4-mercaptobutyl GSL, particularly lines 28615 and 28619 noted more than > 17 μmol·g⁻¹ DW. The sum of three major GSLs (glucoraphanin, glucoerucin, and dimeric 4-mercaptobutyl GSL) attributed > 8 μmol·g⁻¹ DW in all rocket salads, especially ‘Herb-Fragrant Vegetable’ and line 28613 (87 and 93% respectively) in the total GSL accumulation, likewise line 28612 and 28620 attributed > 90%. Indolyl GSLs were ranged 0.27–1.09 μmol·g⁻¹ DW, accounted less than 6% of the total GSLs in varieties and lines. These results provide valuable information regarding the potential beneficial GSL contents individually in different varieties and lines of rocket salads.