L-ascorbic acid in wines offers an antioxidant action that is efficient, immediate and even more intense than sulfur dioxide, even though it cannot substitute it. In comparison to sulfur dioxide it is a reversible antioxidant, therefore if it is found in a medium without an irreversible oxygen accepter (for example, sulfur dioxide), its oxidated form (dehydroascorbic acid) can become a potent oxidant that can produce peroxide. Therefore when used it is essential to also have free sulfur dioxide present at the same time. Ascorbic acid can prevent iron haze and this action is accentuated by the simultaneous presence of citric acid.
The objective of this study was to elaborate and optimize a rapid method to determine ascorbic acid using spectrophotometry.