Study On Storage Techniques Of Litchi With Ultrasound And Ozone Water Under Low Temperature

Using the ozone water and ultrasound as the main fresh-keeping means study their effects on physiology and quality of Litchi (Litchi chinensis Sonn.cv.Guiwei) in this paper.The paper involves: 1) to investigate the effects of ultrasound on physiology ; 2) to study the effects of ozone water on the main enzyme activity related to browning and quality of litchi; 3) to study the responses of the physiological changes of litchi to ultrasound and during the preservation of litchi. The results are as follow:1, Effects of ultrasound on physiology of litchi fruitsThe treatment by ultrasound can inhibit the decline of anthocyanogen content and the activity of PPO, however, the treatment is not effect on the content of SSC and TA significantly. The effect by treatment with ultrasound 1200*600 for 2min or 3min is better than other treatments.2, Effects of ozone water on physiological changes of litchi during the cool preservation.The results show that ozone water can retard the decreasing of anthocyanogen content, holding on effectively the red color of pericarp litchi (cv Geiwei). The results also suggest the process has significant effective by 1.0mg/L5minor3min.ozone water restrain PPO and POD activity, which is lower significantly than CK's by 1.0mg.L" of concentration of ozone water. So the content of anthocyanogen is higher than that of CK.The study all shows that ozone water affect significantly on the soluble solids content (SSC) of litchi fruits, and the of tiratabie acidity (TA) content. These suggest the nutritional quality of litchi fruits is held on by the process of ozone water.3, Effects of ultrasound and ozone water on the preservation of litchiProcessed by ultrasound and ozone water, the browning index of litchi is reduced during the preservation. The results suggest the two treatmental means can effectively retard browning of litchi pericarp. The effect by treatment with ultrasound 1200*600 for 3min and 1.0mg/Lozone water for 5min is better than other treatments.The treatments with ultrasound and ozone water can retard the PPO and POD activity better than others. Considering the front the results relating to the effects of these treatments on browning index of litchi pericarp, the rising of PPO and POD activity accelerate the browning of litchi. Therefore, the content of anthocyanogen is higher than that treated by ultrasound or ozone water.The actions of the treatments are not observed on the reducing the relative permeability of cell membrane in pericarp. The results indicate that the treatment effects on membrane with ultrasound and ozone water are not great difference with the treatments effects with ultrasound or ozone water.After processed by ultrasound and ozone water the nutritive materials are maintained because of the effects of ozone water. But the results also show that the effects with the treatments by both ultrasound and ozone water is not great difference by ultrasound or ozone water on the soluble solids content (SSC) and tiratable acidity (TA) content.Integrating the all results of study, mean adopted in the paper is preferably effective on the preservation of litchi. The mean is better than others, it improve the technique of keeping litchi fruits fresh. And as one of the measures of keeping litchifruits fresh, the technique deserves to study and discuss further.