Abstract

A simple and repeatable method of extracting sulforaphane from cabbage and broccoli was developed and two inbred lines of broccoli with higher sulforaphane content in their seeds were found. The determination method was reverse-phase high performance liquid chromatography (RP-HPLC). In the extraction process, low toxic solvent ethyl acetate was applied for extraction of sulforaphane. The result showed that the linear equation was Y = 5907.07X + 4556.71, R² = 0.9996 assistant with HPLC conditions, and there was a stable and repeatable HPLC condition with the recovery of 96.3% (n = 6, relative standard deviation (RSD) = 1.3%). The better hydrolysis conditions for sulforaphane generation were at pH 7.0, the ratio of buffer to materials (ml/g) 5 to 20:1 and reaction time 1.0 to 2.0 h at room temperature. Finally, eighteen cultivars of cabbage and twelve cultivars of broccoli were used for verification of sulforaphane exaction method. All the materials were proved that they all contained sulforaphane composition and two cultivars of broccoli were proved to contain higher sulforaphane in seeds than previous reports.

Key words: Glucosinolate, sulforaphane, Brassica, broccoli, cabbage, reverse-phase high performance liquid chromatography (RP-HPLC)