Speaking from the chemical point of view, the effects reported
for such molecules in Fig. 1a seem connected quite well with their
molar concentration. Glutathione molar concentration in the sample
at 50 mg/L, the one with the lowest radical scavenging activity,
corresponds to approx. 0.16 mM. Ascorbic acid and sulphur dioxide
at 50 mg/L, were 0.28 and 0.78 mM respectively and determined a
greater percentage of discolouration; the higher efficiency of the
former, despite its lower molar concentration, confirms the higher
capacity of ASC to scavenge free radicals (Vivas et al., 2001).
Finally, GSH at 500 mg/L (1.6 mM) and the same quantity of SO2
(7.8 mM) showed an increasing activity in DPPH bleaching.