Studies On The Changes Of Quality And The Technic Of Controlling During The Storing And Machining The Persimmon

Persimmons have good nutrition and health protection function, which contain abundant nutriments. Study the four storage methods which are freeze-storage, fluid-storage, refrigeratory-storage, gas-refrigeratory storage by taking the persimmon as the material. Find the best storage methods and storage conditions though researching the influence which four methods bring to the persimmon quality during the storage. Text also studied the enzymology characteristic of PPO and the method which could control the browning during the process of gas- refrigeratory storage. Experiment studied the changes of persimmon quality during the process of gas- refrigeratory storage, which used hardened materials, and maked sure the best hardener, concentration and dip in- time. Finally, research the influence of eliminating the persimmon acerbity which carbon dioxide produced to persimmon quality and ascertained the best conditions of carbon dioxide concentration and time.The main study results were as follows:1,Study on the storage method of persimmon. It showed that the gas- refrigeratory storage method could restrain the breath intensity, suspend the respiration rate and stave the growth of persimmon, which ould slower the metabolism of fruit and maintenance the inhere quality and color and luster.2,Study on the enzymology characteristic of PPO in persimmon and the method of control the browning of fruit. The best befitting condition of PPO in persimmon were: temperature 19℃, pH 6.5, concentration of substence 12mmol/L. Deal the persimmon with 0.1% sodium sulfite and 0.3% Phytic Acid, which could restrain the activity of PPO effectively and slower the browning of persimmon during the storage process. And that the method of scald could not make the PPO in persimmon lose the activity. So the restrain function of scald method was not obviously and could intenerate the persimmon , which went against the storage, conveyance and process of persimmon fruit.3,Study on the best conditions of hardening disposal. Persimmon fruit was dipped in 0.2% CaCl2 liquor for 10 hours. Ca2+ could come into being the reticulation configuration, which slowered the loss of water in persimmon , kept the rigidity of fruit , controlled the happening of browning and suspended the rapidity of dissolubility dannic transform to infusibility dannic ,which could keep the good quality of persimmon during the gas- refrigeratory storage process.4,Study on the best method of eliminating the acerbity of persimmon by carbon dioxide. Fresh persimmon could eliminating the acerbity by 60% carbon dioxide at 25℃for 24hours, which could keep good intrinsic quality and appearance of persimmon and could be propitious to storage and process of persimmon. The temperature was the mostly factor to influence the time which persimmon eliminated the acerbity and rigidity of persimmon. The higher the temperature was, the time which was eliminated acerbity spented shorter with a certain concentration of carbon dioxide. The persimmon could be eliminated the acerbity completely at 40℃for 12hours. But the higher temperature was, the fast the rigidity of persimmon which had disposed acerbity dropped. When the temperature was than 35℃, persimmon fruit could lost the rigidity.