Sulfur Dioxide Inhibition of Anthocyanin Degradation by Phenolasea

Abstract
SUMMARY: The degradation of cyanidin 3‐gentiobioside by mushroom phenolase in a model system containing catechol is inhibited by SO2. In a citrate phosphate buffer, pH 6.5, with 2.8 × 10−5M catechol and 3.3 mg commercial enzyme per 100 ml reaction mixture, 8 ppm of SO2 completely checked the anthocyanin degradation. In tart cherry juice, under similar conditions but with no catechol added, 30 ppm SO2 were required for a practically complete inhibition. At lower pH the inhibition is accomplished by smaller SO2 concentrations.