Quality of jujube wine with hydrostatic pressure and freezing treatment.

摘要

Treatment of jujube wine using hydrostatic pressure (500 MPa for 5 min) or freezing (at -20 degrees C for 3 days, followed by thawing at room temperature for 4 h) to prevent the deterioration of wine quality caused by commercial heat sterilization was investigated. Microbial count, physicochemical properties and sensory quality were studied in comparison to heat-treated jujube wine (63 degrees C, 10 min) and commercially sterilized wine. Pressure treated and commercial jujube wine were completely sterile. Microbial count in heat-treated wine was reduced to <10 cfu/ml, while freeze-treated jujube wine was partially sterilized (30-60%). Hydrostatic pressure, freezing and heat treatment had no influence on physicochemical properties and chemical composition (including pH, acidity and amino acid, reducing sugar and ethanol content), but significantly induced colour changes. Heat treatment caused significant deterioration to jujube wine, reducing sour and burning taste. Pressure and freezing treatments of jujube wine caused no loss in sensory quality, with no decrease in sour and burning taste.