What exactly makes Polyphenols special?

Aside from the fact that Polyphenols contribute to the taste and color of the wine; they are also exceptional antioxidants. Antioxidants are substances that may inhibit or delay some types of cell destruction. What exactly do Antioxidants protects cells from? Radicals. Radicals are an uncharged molecule (highly reactive and short-lived) that has an unpaired valence electron. Free radicals are extremely reactive with cellular structures because they contain unpaired electrons. They are natural by-products of reactions in the body such as, metabolic processes and immune system responses. Free radical-generating substances are everywhere. They’re found in the food we eat, the medicines we take, the air we breathe, and the water we drink. Fried foods, alcohol, pesticides, and air pollutants are all examples of free radical-generating compounds. Free radicals can cause damage to parts of cells such as proteins, DNA, and cell membranes. They do this by taking their electrons through a process called oxidation. This type of damage is called “oxidative damage”. When free radicals oxidize essential parts of the cell, those components cease to function normally. If such damage is allowed to accumulate it may eventually cause the cell to die.The polyphonic compounds in wines act as “Radical scavengers”. They find these radicals, and react with them to form compounds that cells can safely dispose off. A sample of this reaction can be summarized by:

R• + PhOH → R-H + PhO•

Where R• would be the Radical and PhOH would be the polyphenolic compound. Notice the PhOH donates a hydrogen to the Radicle to stabilize it (resulting in the less harmful compound R-H that can easily be disposed of). Now wait, what about the PhO•? Isn’t that a radical now? Not exactly. In this particular example the PhO•

This reducing property of the wine can easily be observed by leaving a bottle of wine open for a few days. After a while, individuals can observe browning of the wine and a loss of specific flavors. This can be explained by these polyphenolic compounds being oxidized in air.