Abstract: The relation ship between the changes of composition and ethanol accumulation in both the flesh and pericarp during winter jujube storage was investigated. The results showed that the ethanol content in the flesh increases gradually, while the pyruvic acid and acetaldehyde contents first increase with the delay of storage time, and then decline. The lignin content in flesh and the activity of phenylalanine ammonia-lyase also increase. The healthy and senile tissues of pericarp were observed respectively with the optical microscoped and the results showed that the color of senile pericarp reddens and the cell structure loosens with enlarged intercellular space and even cracked in between. So it was conjectured that a lot of collective microzymes enter the softening tissue of winter jujube so as being led to enthanol accumulation.

Key words: winter jujube, storage, ethanol accumulation, microorganism invade and infect