The effect of high hydrostatic pressure processing on inactivation of microorganisms in raw milk
Effect of high hydrostatic pressure (HHP) processing on inactivation of microorganisms in raw milk was investigated.The raw milk samples were subjected to HHP treatment of 500 MPa for 5,10,15 min at 25 ℃.Microbiological analyses were carried out at 1,3,5,7 days of refrigeration (2～6 ℃).The results showed that HHP reduced total bacterial count in raw milk by about 1 log cfu/mL,and almost killed all of coliform,yeast and mold.Extension of time for HHP could increase the inactivation of bacterial in raw milk.After 500 MPa treatment with 10～15 min,total bacterial count of milk was less than 5.0×104 cfu/ mL during storage at 2～6 ℃.