Decrease in the number of microbial cells on chinese cabbage by rapid hygrothermal pasteurization using saturated water vapor

Decontamination effect of rapid hygrothermal pasteurization using saturated water vapor (RHP) treatment on Chinese cabbage was compared with that of sodium hypochlorite (NaClO) solution. RHP treatment was performed by passing Chinese cabbage sample through a processing chamber saturated with water vapor. NaClO treatment followed by RHP treatment was also performed. RHP treatment showed greater or equal decontamination effect compared to NaClO solution on mesophilic bacteria, coliform bacteria, lactic acid bacteria and yeast. NaClO followed by RHP treatment showed higher decontamination effect compared to RHP treatment or NaClO solution only. No significant decontamination effect on bacterial spores was observed after the all treatments tested. The cutting of Chinese cabbage to smaller size resulted in increasing the effect of RHP treatment. On the other hand, wetting the surface of Chinese cabbage by water reduced the effect of RHP treatment.