Phenolic content in wine - quercetin. Like other flavonoids, the concentration of flavonols in the grape berries increases as they are exposed to sunlight. Some viticulturalists will use measurement of flavonols such as quercetin as an indication of a vineyard's sun exposure and the effectiveness of canopy management techniques. Anthocyanins are phenolic compounds found throughout the plant kingdom, being frequently responsible for the blue to red colors found in flowers, fruits and leaves. In wine grapes, they develop during the stage of "veraison" when the skin of red wine grapes changes color from green to red to black. As the sugars in the grape
The Fox and the Grapes Phaedrus (IV.3) which is terse and to the point: In her version of La Fontaine's Fables, Marianne Moore underlines his ironic comment on the situation in a final pun, "Better, I think, than an embittered whine". Although the fable describes purely subjective behaviour, the English idiom "sour grapes" which develops from the story is now often used also of envious disparagement to others. Similar expressions exist in other languages, but in the Scandinavian equivalent the fox makes its comment about rowanberries since grapes are not common in northern latitudes. The French fable of La Fontaine (III.11) is almost as concise