High hydrostatic pressure as a hurdle for Zygosaccharomyces bailii inactivation

The combined effects of high hydrostatic pressure (HHP, 172, 345, 517 or 689 MPa), duration of HHP treatment (0, 2, 4, or 10 min), water activity (a(w), 0.98 or 0.95), and potassium sorbate (PS) concentration (0 or 1000 ppm) on Zygosaccharomyces bailii inactivation were evaluated at pH 3.5 and 21 degrees C in laboratory model systems. Inactivation of the initial inoculum (= 1.0 x 10(5) CFU/mL) occurred when the pressure was 689 MPa regardless of a(w), PS or duration of treatment. Lower pressure was required for Z. bailii inactivation in the presence of PS.