Dihydrochalcones relationship

Table XVI shows two experiments which compared the same wine stored under different conditions (46). In both cases, the wine richer in anthocyanins is also that which is less colored. The mediation of tannins is not enough to explain the differences in color these can only be explained by a different structuring of the anthocyanin molecules. More specifically, the anthocyanin molecules will be reduced to colorless flavenes (14) during fermentation, which is a reductive process. The reoxidation occurs more rapidly in wooden casks which allow better oxygen penetration than metal storage tanks or large capacity casks. However, the flavenes themselves are relatively instable and can be irreversibly hydrolyzed into dihydrochalcones (16). This explains the lack of relationship between anthocyanin concentration and color, independent, of course, of the eventual appearance of free sulfur dioxide.

DuBois GE, Crosby GA, Saffron P. Non-nutritive sweeteners taste-structure relationships for some new simple dihydrochalcones. 

The only other types of flavonoid substances which have to be considered are benzalcoumaranones (aurones, c/., Bate-Smith and Geissman, 1951), e.g., sulphuretin (XIII, R = H) and aureusidin (XIII, R = OB), chalcones, e.g., butein (XIV), and dihydrochalcones, e.g., phloretin (XV). The relationships between these types are admirably illustrated by Geissman and Hinreiner (1952). Table II is a somewhat modified... 

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