Abstract: Through optimization of sample pretreatment conditions as well as spiked recovery experiments, a two-step extraction method was proposed to detect the sulforaphene (SFE) content in radish seed oil. The effect of radish seed pretreatment on SFE production was investigated. Acetone, dichloromethane, diethyl ether, and n-hexane were separately used to extract crude oil from pretreated radish seeds, in order to compare the effects of conventional refining and anhydrous room temperature refining on the retention rate of SFE in the oil. The results indicated that when detected using two-step extraction with water followed by dichloromethane radish seed oil showed good peak shape, high response value and good recovery and repeatability. The optimal water adjustment and pretreatment conditions that provided maximum SFE content were as follows: directly spraying crushed radish seeds with water to a moisture content of 8%, and then enzymatically hydrolyzing it at 25 ℃ for 10 min. Acetone was found to be the best extraction solvent, giving an SFE content of up to 832.36 mg/kg in the crude oil. SFE in the oil was completely lost after the first step of hydration degumming in the conventional refining process. However, the SFE content of the oil refined by anhydrous room temperature refining was 760.35 mg/kg, with a retention rate of SFE of up to 91.3%. Besides, the basic indexes of the refined oil could reach the national standard for the third grade of edible oil. This study provides useful guidance for the processing, development and utilization of radish seed oil.

Key words: radish seed oil; sulforaphene; processing steps