SOD activity of wine: it’s all in the mix

Abstract

Wine is widely known for its antioxidative characteristics. However, assessment of these properties is mostly indirect and lacks standardization. The most common methods, such as DPPH, ORAC, ABTS, or DMPD assays, yield results that are difficult to compare due to differences in methodology and in the underlying chemical reactions.[1] In our previous work, we established a direct and comparative method by combining stopped-flow measurements with time-resolved UV/vis spectroscopy, allowing precise monitoring of the decay of superoxide under physiological conditions.[2] This approach enables determination of catalytic superoxide-dismutase (SOD) activity, i.e. true turnover-based superoxide conversion, in contrast to the purely stoichiometric radical scavenging behavior typically observed for individual antioxidants, including polyphenols. Therefore, we can determine the catalytic superoxide-dismutase (SOD) activity of substances which mimic the function of native SOD in vitro. Our research shows that certain wines exhibit such catalytic properties. This behavior is unique to wine as a mixed formulation and is not observed when its polyphenolic constituents are examined individually, despite their well-documented antioxidant capacity.[3–5] Moreover, alcohol-free wine possesses higher SOD activity than traditional wine. Our method provides a new standard for quantifying wine’s antioxidant behavior beyond classical scavenging assays and suggests alcohol-free wine as a particularly relevant model system for further investigation, especially from a public health perspective. [6,7]