High hydrostatic pressure pasteurization of red wine

Pasteurization of low alcohol wine using a high hydrostatic pressure (HHP) process was studied. A total of 10 mL grape wine sealed in a nylon/LLDPE bag was placed inside the HHP chamber. The pressure applied to the treatment chamber was maintained at 1000 to 3500 atm for 0 to 30 min. The effects of HHP treatments on the physiochemical properties (Alcohol, pH, acidity, total sugar) and microbes (aerobic bacteria, yeast, and lactic acid bacteria) were examined. The HHP treatments had little impact on the physiochemical properties. The pasteurization effect of the HHP treatments increased with treatment pressure and time. A total of 2 different stages in the microbial inactivation were noticed when the 1st order reaction model was used to fit the inactivation data. The inactivation rate was higher in the initial stages than in the later stages, suggesting that might be 2 different groups of the microorganisms, a more HHP-susceptible group and less HHP-susceptible group.