Thermally treated wine retains antibacterial effects to food-born pathogens

Abstract

Although cooking with wine and consumption of wine as a warm beverage is widespread, antibacterial effects of thermally treated wine have not been studied. We examined in vitro antibacterial activity of wine heated at 75 and 125 °C for 45 min against Salmonella enterica serovar Enteritidis and Escherichia coli. Their effects were compared with intact red wine, dealcoholized wine (DW) and dealcoholized wine reconstituted (RDW) with water to the initial volume. Samples were also analysed for their phenolics content, antioxidant capacity, resveratrol and ethanol content and pH. Total phenolics concentration and related antioxidative activity followed changes in samples volume, regardless of treatment type, while pH of all samples remained stable and ranged from 3.09 to 3.24. The order of the antibacterial activity of wine samples was: intact wine > heated at 75 °C > heated at 125 °C > DW > RDW. Antibacterial activity of the samples could not be related to their content of resveratrol as a single phenolics compound, antioxidative capacity or pH. Thermally treated wine under conditions applicable to food processing in everyday life, may be effective antibacterials in spite of significant heat-induced changes in their physical–chemical composition.