Stabilisation microbiologique des vins par utilisation de champs électriques pulsés

Abstract

For more than ten years, pulsed electric field (PEF) technology has been the subject of a growing number of publications and patents. The technology previously reserved for laboratories is becoming more and more popular and is now a success in the food industry. Since 2015, with the help of the Occitania region, we have been studying the use of the PEF on the microbiological stability of wines on a semi-industrial scale from 5 to 12 hl/hour. This low thermal and energy consuming physical technology requires no inputs to ensure the destruction of microorganisms and microbial stabilization of wines. These tests are performed with a 7 kV/cm electric field generated between the 2 electrodes of the treatment chambers. The objective is to ensure the microbial stabilisation of wines not exceeding 50 ^∘C and to cool the wine immediately after treatment without maintaining it at high temperature. The study of the effectiveness of PEF on yeast destruction is carried out during the mutage of sweet wines. The first results obtained show a very good efficiency of the yeast treatment with an instant cessation of alcoholic fermentation and a decrease in the yeast population ranging from − 3 to − 5 Log. No SO₂ addition is then required. On wines contaminated by Brettanomyces, the tests show an almost total elimination (< 1/100 ml) of these yeasts by the PEF treatment. These tests also showed that a higher energy level is required to eliminate all lactic acid bacteria from wine. No effects on the physico-chemical characteristics of the wines were found. The impact on the organoleptic characteristics of wines is ongoing. An optimization of the electrical parameters is still necessary.