Mise au point d'une mesure rapide de l'activité laccase dans les moûts et dans les vins par la méthode a la syringaldazine. Application à l'appréciation de l'état sanitaire des vendanges

Abstract

The syringaldazine assay has been adapted for quantitative determination of laccase activity from Botrytis cinerea, in must and new wines. This colorimetric method is fast, specifie and sensible. It allows to appreciate the level of contamination of the crops by Botrytis cinerea.

The assay can be performed in presence of tyrosinase but the phenolic compounds of the grape must be discarded because of their inhibitor effects on syringaldazine oxidation by laccase.

So measured in botrytised grapes juices, laccase activity is related with the stages of development of the fungus.