Also the results of Vivas, Saint-Cricq de Gaulejac, and Glories
(1997) are in disagreement with the radical scavenging capacity
of sulphur dioxide, reported in Fig. 1a. Studying the influence of
SO2 and ascorbic acid on the scavenging effect of tannins, they
wrote that, at usual enological concentrations, sulphites do not
have a scavenging effect on superoxide anion. Nevertheless,
according to literature, superoxide radical reacts very slowly with
sulphite (SO32) and the rate constant of the reaction is very low
(82 M1 s1) (Neta & Huie, 1985).