Argon gas plasma to decontaminate and extend shelf life of milk

Abstract

Treatment of milk with argon gas plasma was investigated for its ability to kill bacteria and increase shelf life and compared with commercially pasteurized milk. The discharge was generated by a nanosecond pulse generator using the needle point-to-plate electrode. The total bacterial count of 6.8 log CFU/mL in raw milk was reduced to 1.9 log CFU/mL after 2 min of plasma treatment and 2.2 log CFU/mL after 30 min of pasteurization. The plasma treated milk stored at 4 °C showed no significant changes in the bacterial count for 6 weeks while the bacterial counts in pasteurized milk were significantly increased from 2.2 to 4.2 log CFU/mL after 2 weeks. These results demonstrated plasma treatment as an alternative way to decontaminate and increase shelf life of milk.