Inactivation kinetics of L. innocua NCTC 11289 (A), S. cerevisiae SU 51 (B), E. coli NCTC 9001 (C), and L. plantarum LA 10-11 (D) in phosphate buffers at different pH values. Symbols: ■, pH 4.0; ■, pH 4.4; ⧫, pH 5.0; ●, pH 6.0. The electric field strength was 2.2 to 2.7 V/μm, the conductivity of the phosphate buffer was 0.78 S/m at an inlet medium temperature of 40°C, and the pulse length was 3.9 μs. The L. innocua NCTC 11289 inoculum contained 1.6 × 106 CFU/ml, the S. cerevisiae inoculum contained 106 CFU/ml, the E. coli inoculum contained 1.2 × 105 CFU/ml, and the L. plantarum inoculum contained 4.2 × 106 CFU/ml (pH 4.0) or 1.0 × 107 CFU/ml (pH 4.4). The results are means based on data from two experiments, and standard deviations are indicated by error bars. Nt, number of survivors after treatment; N0, number of cells before treatment.