Study on sterilization of bacterium in milk by supercritical CO_2

Sterilization effects on bacterium in milk of supercritical CO2 was studied.The effects of pressure,sterilization time and sterilization temperature on sterilization rate was pre-tested through single factor experiment.Then,orthogonal experiment was used for the optimal sterilizing condition.At the same time,nutritional ingredients in milk were analyzed after sterilization.Results showed that,sterilization rate of bacterium in milk was 99.8%,and nutritional ingredients in milk were lost few,when it was under the optimal sterilizing condition:pressure 35MPa,sterilization time 140min and sterilization temperature 45℃.Therefore,bacterium in milk can be sterilized by supercritical CO2 effectively,loses of nutritional ingredients can be also decreased.