Study On Post-harvest Physiology And Storage Techniques Of 'Dongzao' Jujube

The effects of hypobaric, hot-water treatment, ozone, chlorine dioxide on post-harvest senescence physiology and edible quality changes were investigated. The results were as follows:1. Hypobaric storage significantly kept firmness and content of vitamin C, reduced respiration rate, inhibited the increasing of sugar content between–0.5℃and 0.5℃. After storage, the percentage of jujubes with no defects of control and treatment of ventilating once a day were 12%, while the percentage of jujube with no defects of treatment of ventilating once every two days and every three days were 40% and 63%. The percentage of softened jujube of control was 80% and smelt full-bodied alcohol, while the jujube with hypobaric treatment had no softened jujube. On the other hand, the percentage of rotten jujube of hypobaric treatment were much higher than control, the percentage of rotten jujube of jujube with treatment of ventilating once a day was the highest at 88%, while the treatment of ventilating once every three days was the lowest merely at 37%. Owing to the different interval ventilation time, the quality of jujube was different at the end of storage. Results showed that the respiration rate of jujube with treatment of ventilating once every three days was the lowest, the increasing of sugar content and reducing of firmness and reducing of vitamin C content were the slowest, the percentage of good jujube was the highest.2. Results showed that'Dongzao'Jujube immersed in hot-water for several minutes could control the decay and keep the respiration at lower level than that of control. Hot-water treatment significantly kept firmness and content of vitamin C, inhibited the increasing of ethanol and acetaldehyde during storage. The appropriate temperature and time was 50℃6 minutes. The sound fruit rate of hot-water treatment was 82% after storage, while the control only 7%, the difference was significant. 3. In this study, the temperature was controlled between -0.5℃and 0.5℃. Under this humid-cool storage conditions, ozone could postpone the decline of firmness, reduced the percentage of rotten jujube and brown jujube. The quality of jujube treated with 3 mg/m3 ozone once a day was the best. After 81 days, the percentage of whole-red jujube and rotten jujube and brown jujube and fermented jujube of the control were 25.1%,37.1%,24%,64% respectively, while the jujube treated with 3 mg/m3 ozone once a day were 6.7%,14.15%,16%,22%, the firmness and sweetness and the percentage of crisp jujube were 19.66%,3.6% and 12.6% higher than control.4. The effects of chlorine dioxide (ClO2) treatment(50ppm,100ppm) on storage qualities of'Dongzao'Jujube were investigated during cold storage. Results showed that ClO2 treatment could significantly control the decay and keep firmness,vitamin C and total soluble sugar content during storage. The sound fruit rate of ClO2 treatment was 100% after 88d's storage, while the control only 37.2%, the difference was significant.