| Kiwifruit is rich in nutrition,unique flavor,and has obvious ripening process.It is easy to soften,rot and short storage period after harvest.Transportation vibration will accelerate the physiological ripening of kiwifruit and greatly shorten the shelf life of kiwifruit.In this study,’ Xuxiang ’ kiwifruit was used as experimental material.The effects of different vibration time and different cushioning packaging on the quality of kiwifruit during storage after logistics vibration were compared,and the effect of cushioning packaging on malic acid metabolism in kiwifruit was studied.The main research results are as follows:(1)Effect of vibration time on storage quality of kiwifruit.The vibration parameters were set by simulating the actual transportation conditions,and the vibration treatment of 0 h,24 h,48 h and 72 h was used.The physiological changes of kiwifruit during storage were studied and the prediction model was established by measuring the storage quality.The results showed that vibration treatment decreased the storage quality of kiwifruit.Specifically,hardness decreased,pulp color changed,weight loss rate and decay rate increased,relative conductivity and MDA content increased,total phenol content and VC content decreased,and cell wall degradation accelerated.It can be inferred that the logistics transportation time is negatively correlated with the storage period of fruit.In addition,the hardness and titratable acid of the fruit in the 72 h vibration treatment group were significantly decreased when the vibration was just finished and the storage was not started.When the logistics vibration time was greater than 48 h,the fruit might be damaged immediately.In order to prolong the shelf life of kiwifruit,the logistics time should be minimized,preferably within 48 h,and cushioning packaging should be used to reduce the damage caused by transportation vibration.(2)Effects of cushioning packaging on storage quality and antioxidant activity of kiwifruit.Foamed polyethylene(EPE),foam bag and Expanded polystyrene(EPS)were used as three commonly used cushioning packaging in current e-commerce logistics to protect kiwifruit.Without cushioning packaging,the kiwifruit was treated with vibration for 72 h,and the effect of EPE cushioning packaging on the changes of kiwifruit indexes was studied.The results showed that the three kinds of cushioning packaging could protect kiwifruit to a certain extent,delay the decrease of hardness and the change of flesh color,as well as the changes of TSS and TA content,delay the decomposition of VC and phenolic compounds,reduce the oxidative damage of cell membrane,maintain the antioxidant capacity,and improve the storage of kiwifruit.Comprehensive analysis of the results of various indicators,EPE cushioning packaging effect is the best,followed by EPS,foam mesh bag is poor.(3)Effects of EPE cushioning packaging on organic acid metabolism of kiwifruit.Using EPE cushioning packaging and pure carton packaging as control,the vibration parameters were set to simulate the actual transportation conditions,and the storage was carried out after72 h vibration.The effects of cushioning packaging on organic acid metabolism of kiwifruit were analyzed by measuring the content of organic acids,the activity of main organic acid enzymes and the expression of related enzymes genes.The results showed that malic acid was the main organic acid of ’Xuxiang’ kiwifruit.The malic acid metabolism-related enzyme activity and gene expression of kiwifruit in EPE cushioning packaging group were relatively stable during storage,and the fluctuation range was small,but the fluctuation of the control group was large,indicating that the fruit had a strong physiological response,which was inconsistent with the normal ripening metabolism.It can be considered that EPE cushioning packaging maintained the stable operation of malic acid metabolism in kiwifruit fruit cells. |
