Comparison of the effect of pulsed electric field or high voltage electrical discharge for the control of sweet white must fermentation process with the conventional addition of sulfur dioxide

• Fermenting sweet wine was treated by PEF, HVED and SO2 for microbial yeast inactivation.
• SO2, PEF and HVED decreased the total yeast amounts up to 8, 3 and 4 logs respectively.
• The non-Saccharomyces yeast amounts were decreased after SO2, HVED and PEF up to 7, 5 and 4 logs respectively.
• No wine's browning was observed for PEF treated samples only.

The present work discusses the efficiency of pulsed electrical treatments for the inactivation of yeasts. The application of pulsed electric fields (PEFs) and high voltage electrical discharges (HVEDs) as alternatives to sulfites, which are used as anti-microbial to stop the fermentation of sweet white wine, was investigated. The influence of sulfite concentration (from 0 mg·L− 1 to 500 mg·L− 1), PEF (from 4 kV·cm− 1 to 20 kV·cm− 1; from 0.25 ms to 6 ms) and HVED (40 kV/cm; 1 ms or 4 ms) treatments on the inactivation of total yeasts and non-Saccharomyces yeasts was determined. The addition of SO2 (250 mg·L− 1) resulted in 8 log total yeast reduction. The maximum yeast inactivation obtained with PEF and HVED was respectively 3 and 4 logs. The use of SO2, HVED and PEF allows decreasing the non-Saccharomyces yeast level by 7, 5 and 4 logs respectively. However, the wine browning was less pronounced for the samples treated by PEF in comparison with HVED and SO2 treatments. PEF seems to be the most suitable alternative technique to sulfite addition.