Enhancement effect of carvacrol on yeast inactivation by mild pressure carbon dioxide

Saccharomyces cerevisiae is one of the common spoilage microorganisms in fruit juices. This paper investigated the influences of carvacrol on S. cerevisiae inactivation by mild pressure carbon dioxide (MPCO₂). The results demonstrated that carvacrol synergistically enhanced the antifungal activity against S. cerevisiae of MPCO₂. With the increase of carvacrol concentration (20–160 µg/mL), CO₂ pressure (1.5–3.5 MPa), process temperature (20–40 °C), and treatment time (15–60 min), the inactivation effect of carvacrol combined with MPCO₂ on S. cerevisiae was gradually increased and significantly stronger than either single treatment. In the presence of carvacrol, MPCO₂ severely disordered the plasma membrane of S. cerevisiae, including the increase of membrane permeability, and the loss of membrane potential and integrity. MPCO₂ and carvacrol in combination also aggravated the mitochondrial depolarization of S. cerevisiae and reduced intracellular ATP and protein content. This study suggests the potential of carvacrol and pressurized CO₂ as an alternative technology for food pasteurization.