Effect of Combined Treatment with Cinnamon Oil and petit-High Pressure CO(2) against Saccharomyces cerevisiae

This study investigated the effects of the combined treatment with cinnamon oil (CIN) and petit-high pressure CO(2) (p-HPCO(2)) against Saccharomyces cerevisiae. The results showed that CIN and p-HPCO(2) exhibited a synergistic antifungal effect against S. cerevisiae. After being treated by CIN at a final concentration of 0.02% and p-HPCO(2) under 1.3 MPa at 25 °C for 2 h, the S. cerevisiae population decreased by 3.35 log(10) CFU/mL, which was significantly (p < 0.05) higher than that of CIN (1.11 log(10) CFU/mL) or p-HPCO(2) (0.31 log(10) CFU/mL). Through scanning electron microscopy, fluorescence staining, and other approaches, a disorder of the structure and function of the cell membrane was observed after the CIN + p-HPCO(2) treatment, such as severe morphological changes, increased membrane permeability, decreased cell membrane potential, and loss of membrane integrity. CIN + p-HPCO(2) also induced mitochondrial membrane depolarization in S. cerevisiae cells, which could be associated with the decrease in intracellular ATP observed in this study. Moreover, the expression of genes involved in ergosterol synthesis in S. cerevisiae was up-regulated after exposure to CIN + p-HPCO(2), which might be an adaptive response to membrane damage. This work demonstrates the potential of CIN and p-HPCO(2) in combination as an alternative pasteurization technique for use in the food industry.