Saccharomyces cerevisiae thermal inactivation kinetics combined with ultrasound

Inactivation kinetics of Saccharomyces cerevisiae during thermal treatments at moderate temperatures (45.0, 47.5, 50.0, 52.5, or 55.0 degrees C) combi ned with application of 20 kHz of ultrasound were evaluated. S. cerevisiae inactivation under the combined effects of heat and ultrasound followed fir st-order reaction kinetics, with decimal reduction times (D) that varied fr om 22.3 to 0.8 min. D values in treatments that combined heat and ultrasoun d were significantly smaller (P < 0.05) than D values obtained for thermal treatments and were more noticeable at temperatures below 50 degrees C. The dependence of the D value on temperature had a significantly (P < 0.05) gr eater z value for combined treatments. Yeast heat inactivation kinetics rev ealed decreased thermal resistance caused by ultrasound.