Disclosed are methods for stabilizing an oxygen dependent or oxygen-labile pigment from discoloration, and for maintaining the freshness and preventing discoloration of a foodstuff comprising the oxygen-labile pigment. In some embodiments, the method comprises (1) reducing the oxygen concentration in the atmosphere of a sealed container comprising the pigment to a level such that the oxygen will not discolor the pigment when CO2 is introduced into the container, and (2) introducing CO2 into the sealed container while retaining or further reducing the oxygen concentration in the atmosphere of the sealed container. Systems useful in the methods disclosed herein.