Wine and beer contain components that are very susceptible to oxidation. It has been known that given as little as 10 ppm of oxygen and enough elapsed time during distribution, oxidation can occur.
Deoxygenation consists of stripping the excess oxygen dissolved in the liquid by injecting nitrogen or carbon dioxide in the form of tiny bubbles. Using a concentration gradient, these bubbles force the dissolved oxygen into the gas phase which is then vented out from the liquid.
This can reduce the residual oxygen retained in the beverage to as little as 1 to 3 ppm, greatly extending the quality life of the beverage.