Effect of Steaming and Ultrasound Treatment on Sulforaphane and Allyl Isothiocyanate Content of Brussels Sprouts (Brassica oleracea var. gemmifera)

The objective of this study was to investigate the effect of different durations of steaming (ranging from 1 to 10 min) and ultrasound treatments at various intensities (200 w, 400 w, 600 w, 800 w, or 1,000 w) and durations (10, 30, or 60 min) on the levels of sulforaphane (SFN) and allyl isothiocyanates (AITC) in Brussels sprouts. The SFN content continued to increase up to 3 min of steaming time, after which it decreased. However, even after this decrease, the content remained significantly higher (p0.05) than that of the raw sample, reaching its maximum value of 1,095.57±7.24 μg/100 g fresh weight (FW) at 3 min of steaming time. In response to the increase in ultrasonic power intensity, the SFN content exhibited an upward trend, followed by a decrease. The highest SFN content was observed at an ultrasonic power intensity of 200 w and a processing time of 60 min (1,312.78±14.02 μg/100 g FW). Additionally, the AITC content continued to increase up to 3 min of steaming time (466.31±3.34 μg/100 g FW), followed by a subsequent decrease, maintaining a consistent level from 4 to 7 min of steaming time. With the ultrasonic treatment, the AITC content increased until an intensity of 400 w was reached, after which it declined beyond 600 w. The treatment conditions yielding the highest content were identified as 200 w and 60 min. Thus, this study demonstrates that both steaming and ultrasonic treatment can affect myrosinase enzyme inactivation and suggests that ultrasonic treatment may yield higher increases in SFN and AITC content for Brussels sprouts compared to steaming.