Preservative Effects of Allylmustard Oil and Ethanol on "Hiroshimanazuke"

Abstract

Antimicrobial effect of allylmustard oil (allyl isothiocyanate) and ethanol on the microorganisms associated with "Hiroshimanazuke" (salted Brassica campestris L. var. pekinensis Rupr.) was examined. Squeezed juice from "Hiroshimanazuke" was used as a basal medium and microorganisms grown in "Hiroshimanazuke" were employed as test organisms. The growth of microorganisms was significantly inhibited by allylmustard oil even at 5mg/100ml level, and slightly by 2% ethanol. Synergistic antimicrobial effect was recognized between allylmustard oil and ethanol. Allylmustard oil revealed not only bacteriostatic effect toward lactic acid bacteria but also bactericidal effect toward Gramnegative bacteria at 5mg/100ml level. These results suggest that the shelf life of "Hiroshima-nazuke" can be extended for 45 days longer at 10°C by addition of allylmustard oil alone or in combination with ethanol.