Think about taking authentic oolong tea of an apple and leaving it on your kitchen table for a number of hours. Depending on the local weather in your area, completely different adjustments will happen. In a moist place like Florida, the apple will turn brown, turn into soggy, and lose its texture. In a drier area like Texas or Southern California, the apple will shrink slightly, dry out, and develop a thin movie on the uncovered components. These modifications are forms of oxidation, where the apple is exposed to the air.