Pulsed electric field treatment of red wine: Inactivation of Brettanomyces and potential hazard caused by metal ion dissolution

Pulsed electric field (PEF) technology is an attractive alternative method of wine preservation by inactivating Brettanomyces bruxellensis, a major spoilage concern affecting wines worldwide. Currently, wine preservation using SO2 can have negative effects on consumers including headaches and allergic reactions. Therefore, the objectives of this study were to investigate the effect of PEF processing conditions, B. bruxellensis yeast strain and alcohol concentration on B. bruxellensis inactivation in red wine, as well as whether PEF treatment could have a harmful effect on wine through the release of metal ions. Electric field intensity was found to have a greater impact on inactivation than specific energy, with 31, 40 and 50 kV/cm treatments resulting in B. bruxellensis D values of 181.8, 36.1 and 13.0 mu s, respectively. At 50 kV/cm, a temperature rise of almost 10 degrees C, doubled inactivation to 3.0 log reductions (cfu/mL). Yeast strain and alcohol concentration were also shown to influence inactivation, even though cell size comparisons of the three yeasts tested proved inconclusive. Overall, PEF treatment of wine was shown to be a possible preservation alternative for the wine industry. After PEF treatment, the wine produced remained safe for human consumption, with Fe, Cr and Ni ions contents well below dangerous levels.