Study On The Quality Change Of Blueberry Under Different Logistics Mode

The whole process of fruit circulation includes transportation, storage and sales. At present, reducing the loss in the fruit circulation has become one of the main problems in the world. This research is based on the Berkeley blueberry as a material, Two kinds of logistics modes of room temperature chain and cold chain are simulated. Through the analysis of the changes in physical and chemical indexes and the changes of nutrients, the effects of vibration time, packaging mode and temperature on the quality of blueberry in the stage of transport, storage and shelf life were studied.The main research contents of this paper include: Study on the quality change of blueberry in different vibration time at transport stage, Study on quality change of blueberry in shelf life stage under normal temperature logistics. Study on the quality change of blueberry during storage and shelf life under the condition of cold chain logistics.Conclusions are as follows.(1)In the logistics process of transport stage, the quality of blueberry was studied under the condition of two kinds of logistics mode with normal temperature and low temperature. The results showed that the length of the vibration time had a significant effect on the fruit quality,and the sensory scores,hardness, chewing ability,TA and VC contents decreased with the increase of vibration time. Also, the longer the vibration time, the greater the decline range. In addition, the SSC content increased with the increase of the vibration time. Under the same vibration time, the quality of blueberry was compared under different temperature conditions, and it was found that low temperature is conducive to maintaining a high anthocyanin content of blueberries, delaying the decrease of hardness,chewiness, TA and VC content. Wherein the effect of temperature on blueberry VC content is the most significant. In vibration 60 min, compared with the control group, room temperature VC group decreased 26.97%, while the hypothermia group fell 8.85 percent.Experimental results showed that low temperature had a greater significance for maintaining the quality of blueberry. Moreover, the blueberry volatile substances were analyzed. The experimental results showed that the blueberries with different vibration time in the phase of transportation can be distinguished by the electronic nose detection technology, but the different analysis methods had different emphases.(2)At the shelf stage of process of room temperature logistics, Quality of blueberries at shelf stage with room temperature and low temperature were studied. It was found that the rule of blueberry quality changes in two modes of shelf was as follows: With the shelf life extended, the good fruit rate, hardness, chewing ability, anthocyanins, TA and VC content decreased. Moreover, the longer of the vibration time, the faster of the blueberrydeterioration rate in late shelf life. Compared with the control group, the good fruit rate of the group in vibration 40 min is the lowest. Compared with the first day of the shelves, the good fruit rate of vibration 40 min group on the fifth shelf day at room temperature and low temperature decreased respectively 34.02%, 27.55%, Blueberry SSC content showed a trend of first increased and then decreased. Which vibration 40 min group in the shelf life at ambient temperature on the 5th day of SSC content is maintained 11.61%, hypothermia group SSC content is controled in 13.5%. Experimental results show that blueberry shelf quality depends on the length of time of transport vibration, low temperature more than the normal temperature help in holding above-mentioned quality of blueberry. The results also show that the electronic nose detection technology can quickly distinguish the blueberries which with different vibration time and different temperature in shelf stage.(3)In the storage phase of cold chain logistics, quality change of blueberry under different packaging were studied. The study found that compared with the foam boxes packaging(Y1), the quality index including good fruit rate, hardness, SSC, TA and Vc content of blueberries which were packed by foam box and PET plastic box(Y2) in storage stage are higher. However the effect of different packaging methods on the storage period of blueberry is little. On the 54 th day of storage, the good fruit rate of blueberries which were packed by foam boxes was 41.18%, the other group’s was controlled in 56.61%,which packed by foam box and PET plastic box. The results showed that even under the condition of cold chain logistics, the quality of the blueberry was affected by the packaging method. In addition, different packaging methods also have influence on the volatile matter content and types of blueberry during storage. The experimental results also show that using the electronic nose combined with GC-MS detection and analysis technology can realize the rapid detection of different packaging methods and different storage periods.(4)At the shelf stage of cold chain logistics, Quality of blueberries at shelf stage with room temperature and low temperature were studied. It was found that the low temperature shelf and the foam box combined with PET plastic box packaging(Y2) can keep the high quality of blueberry, On the 5th day of shelf life, its good fruit rate remained at 82.17%,while other group’s was only 41.23%, which with normal temperature shelf and using foam box packaging(Y1). At the same shelf temperature, Y2 packaging is more conducive to maintaining higher SSC, TA and VC content of the blueberry in shelf stage. what’s more,different packaging methods had little influence on the hardness, chewing and anthocyanin content of blueberry during shelf life. The results showed that both the different packaging methods and shelf temperature had influence on the quality of blueberry, but its influence degree on the quality index is different. Moreover, the volatile compounds of blueberry during shelf life after storage were studied with qualitative and quantitative analysismethods. The experimental results showed that the using electronic nose combined with GC-MS detection and analysis technology can be achieved on rapid detection of different packaging methods and different shelf life of blueberries.