Water pressure effectively reduces Salmonella enterica serovar enteritidis on the surface of raw almonds

The effects of continuous high hydrostatic water pressure treatments (414 and 483 MPa with a holding time of 6 min) on the viability of two strains of Salmonella enterica serovar Enteritidis (PT 9c and PT 30) inoculated onto raw almonds were evaluated at 25 degrees C. The concentrations of both Salmonella Enteritidis isolates were reduced to undetectable levels when the almonds were directly suspended in water, pressurized at 414 MPa and 25 degrees C for 6 min, and then dried at 115 degrees C for 25 min. When the almonds were pressurized at 414 MPa and dried at 55 degrees C for 5 min, a more than 3.58-log reduction was achieved for both isolates. Increasing the drying temperature to 65 degrees C resulted in a more than 3.96-log reduction for both isolates. Increasing the water pressure to 483 MPa further decreased the Salmonella Enteritidis concentration on the surface of the raw almonds. When the almonds were treated at 414 MPa, the decimal reduction times were less than 35 s for both isolates. High hydrostatic water pressure treatment of certain dry foods appears to be feasible when the food is suspended directly in the pressurizing medium (water).