Despite none of these alternatives has antimicrobial activity (as
instead SO2 has), the opportunity to reduce sulphur dioxide by
their utilization, is arousing more and more interest, among winemakers.
Nevertheless, despite the amount of works reporting the
antioxidant effects of these substances, the most of the papers
regards model solutions and moreover, it is currently difficult to
foresee in which extent it is possible to replace sulphites with each
of these alternatives, preserving wine quality, because of the lack
of scientifically-based direct comparisons, among their effects
and those of sulphur dioxide.
For this reason, the aim of this work was to carry out a preliminary
investigation on the radical scavenging activity (measured by
DPPH assay) and the oxygen consumption capacity of different
enological products and additives in comparison with SO2. Ascorbic
acid (considered as reference standard), glutathione, yeast lees
and a self-prepared yeast autolysate were tested. Trials were
performed in model solution and in different wine typologies.
Concerning oxygen consumption trials, wines were finally subjected
to fast spectrophotometric measurements, for assessing
the effect of the different antioxidants on colour, total phenolics
and predisposition to browning.