KINETIC-ANALYSIS OF ZYGOSACCHAROMYCES-BAILII INACTIVATION BY HIGH HYDROSTATIC-PRESSURE

High hydrostatic pressure inactivation kinetics of Zygosaccharomyces b ailii in food model systems of pH 3.5 and water activities (a(w)) of 0 .98 and 0.95 were evaluated at 21 degrees C and pressures from 241 to 517 MPa. The come-lip time to reach a pressure exerts ts an important effect on the survival fraction of Z. bailii. Yeast inactivation follo wed first order reaction kinetics, with inactivation dependence of the yeast inactivation rates can be described by the apparent activation volume and by a 'pressure z value', revealing in both cases a greater pressure dependence for systems with a(w) 0.98. (C) 1997 Academic Pres s Limited.