Effects of Storage Temperature on Retention of Volatile Isothiocyanates in Salted Cruciferous Vegetables

抄録

Changes in amounts of volatile isothiocyanates were studied in the salted products of Yamagataseisai, Takana, Nozawana and Hiroshimana during their storage at 2°C and -22°C. Volatile isothiocyanates collected by lyophilization were analyzed by gas chromatography, and their relative amounts were compared periodically during the storage. In the case of storage at 2°C, major part of volatile isothiocyanates decreased rapidly in their relative amounts within 35 days, though their decrease rates were slower in Yamagataseisaizuke than Nozawana-zuke and Hiroshimana-zuke. On the other hand, much higher content of voaltile isothiocyanates could be found in the salted vegetables stored at-22°C than in those stored at2°C. In the frozen storage, volatile isothiocyanates were well retained for at least 3 months, though 3-methylthiopropyl, 4-methylthiobutyl, and 5-methylthiopentyl isothiocyanates seemed to be unstable even at-22°C.