Study On The Injury Rate Of Pathogens With UHP In Bovine Milk

At room temperature, effects of intensity of high hydrostatic pressure and its duration were applied to Escherichia coli 1.487, Salmonella choleraesuis subsp choleraesuis 1.1859 and Staphylococus aureus Rosenbah 1.1861 in bovine milk, the variety of the viable count under high-pressure treatment was determined. It was able to obtain the sterilizing effect of pathogens in bovine milk with high hydrostatic pressure process. It turned out: high hydrostatic pressure treatment 500MPa for 20min , the injury rate reached 99.9981% of Escherichia coli 1.487,the initial bacteria number was 4.7×107cfu/ml; its reached 99.9994% of the Salmonella choleraesuis subsp choleraesuis 1.1859, the initial bacteria number was 4.8×107cfu/ml .600MPa for 20min, it reached 99.9925% of the Staphylococus aureus Rosenbah 1.1861, the initial bacteria number was 5.8×107cfu/ml.Being another test, the optimum injury rate parameters (100.00%)were: 500MPa for 20min , the initial bacteria number was 2.9×106cfu/ml of Escherichia coli 1.487; the initial bacteria number was 1.5×106cfu/ml of Salmonella choleraesuis subsp choleraesuis 1.1859. then 600MPa for 15min, the initial bacteria number was 2.5×106cfu/ml of Staphylococus aureus Rosenbah 1.1861.