Inactivation of Zygosaccharomyces bailii in fruit juices by heat, high hydrostatic pressure and pulsed electric fields

Heat, high hydrostatic pressure (HHP) and high pulsed electric field (PEF) inactivations of Zygosaccharomyces bailii ascospores and vegetative cells s uspended in apple, orange, pineapple, cranberry and grape juices were inves tigated. The ascospores exhibited a heat resistance that was more than 5-8 times greater than the vegetative cells. After 5 min of pressurization at 3 00 MPa, the population of vegetative cells decreased almost 5 log cycles, w hile the population of ascospores decreased between 0.5-1 log cycles. In ea ch fruit juice studied, two pulses of 32-36.5 kV/cm decreased the populatio n of vegetative cells or ascospores 3.5 to 5 log cycles.