Effects of high-oxygen treatments on respiration intensity and quality of ‘Dongzao’ Jujube during shelf-life

‘Dongzao’ jujube(zizyphus Jujuba Mill.) were treated with 70％ and 100％ high-oxygen for 7 d and 15 d respectively at -2℃, then the changes of respiration intensity and quality were studied during shelf-life at 20℃. Results show that 70％ O₂ treated for 7 d can increase the respiration intensity, while 100％ O₂ treated for 15 d can inhibit respiration remarkably. 70% O₂ treated for 7 d and 15 d, or 100% O₂ treated for 15 d are beneficial for keeping fruit firmness, but there is little effect on SSC. 100％O₂ treated for 7 d or 15 d is good for Vitamin C reserve, while 70％ O₂ treatment accelerates the loss. High-oxygen treatments inhibit PPO activity increasing, 100％ O₂ treatment has more obvious effect. High-oxygen treated for 15 d has a little effect on fruit decay, but the result is not ideal. Generally, 100% O₂ treatment for 15 d at low temperature is best for freshness preservation when "Dongzao" is on the shelf.