Static and Dynamic, but not Pulsed High-Pressure Treatment Efficiently Inactivates Yeast

Static high-pressure (HP) treatment has become a powerful tool for preserving foodstuffs, allowing high inactivation rates and minimal adverse effects on valuable components. Due to HP maxima and batch mode conditions, it is restricted to high-grade products. To overcome these restrictions, dynamic HP offers the possibility of a quasi-continuous mode of operation. The effects of three different HP treatments (static, pulsed, and dynamic) on yeast were investigated. The inactivation efficiency and membrane damage increase with increasing pressure or pressure holding time. The cells do not show higher sensitivity to fast and repeated depressurization, and the number of pressure pulses plays only a minor role in inducing membrane damage. A form of programmed cell death could not be detected.