The practical shelf life and storage stability of freeze dried pure lemon crystals was studied with a view to possible application of the results in freeze drying of lemon products. The crystals were extremely hygroscopic and exhibited a high tendency to caking on storage at ambient temperature, while under refrigeration they preserved their free flow property and dissolved promptly both in hot and in cold water. With regard to browning deterioration, it was found that low temperature is a decisive factor in its prevention, while low water activity is not enough in itself.Contrary to the effects of temperature and water activity upon the browning deterioration, almost no effect was observed due to inert atmosphere packaging.Browning deterioration at adverse conditions was proceeded by a steep rate of carbon dioxide evolution, thus suggesting that in dehydrated food products, carbon dioxide evolution rates at the lag period could be used as an early indicator for the length of the lag period and the intensity of browning yet to be developed in the course of storage.