Yes, by refrigerating it you will increase its life by as much as 50% If you remove or reduce the causative agents of decay (radiation, microorganisms etc.) then an apple will decay at a slower rate. Dry freezing or storing in a vacuum would increase the lifespan further, keeping away from any sources of radiation (including heat and sunlight) would also help and are more easily achieved by the average person who doesn't have a vacuum chamber to hand.