# Quality Monitoring and Analysis of Xinjiang 'Korla'
## 3 Results and Discussion  
### Temperature and Humidity Analysis of Fragrant Pears Cold Chain Logistics  
The temperature fluctuation over time for fragment pear cold chain logistics is described in Figure 4. The first segment is the ordinary transportation of fragment pears from the orchard to the cold store. The temperature in the first segment mainly varied with ambient temperature from 17.1 \({}^{\circ}\)C to 25.3 \({}^{\circ}\)C. In the second segment (precool), the temperature decreased rapidly from 25.2 \({}^{\circ}\)C to 3.8 \({}^{\circ}\)C and then stabilized. The temperature decreased slightly from 3.8 \({}^{\circ}\)C to \(-\)0.2 \({}^{\circ}\)C in the first third of the third segment (cold storage), then kept stable for the rest of the third segment. The fourth segment (refrigerated transportation process) contains a series of truck transportations. The temperature raised quickly at the beginning and then varied greatly, the lowest recorded temperature was \(-\)0.9 \({}^{\circ}\)C, and the highest 5.3 \({}^{\circ}\)C. In the fifth segment (sales stage), fragment pears were temporarily stored for display and sale, and the temperature rose from 5.2 \({}^{\circ}\)C to 9.5 \({}^{\circ}\)C.  
The relative humidity fluctuation over time for fragment pear cold chain logistics is described in Figure 5. The relative humidity decreased rapidly from the normal value to 90.5% in the first segment  
Figure 4: The change of temperature in the fragment pear cold chain.  
(transportation). At the beginning of the second segment (precool), the relative humidity reduced rapidly while the temperature reduced rapidly, after that, relative humidity ascended quickly due to the energy released by the metabolic activity of fragrant pears. In the first third of the third segment (cold storage), the relative humidity decreased gently from 83.5% to 92.4% and then maintained steady. As there was a series of truck transportation in the 4 th segment, the average relative humidity in this segment was about 93.8%. In the 5 th segment, the relative humidity has an obvious fall in the beginning, and then rose rapidly to 94.5% and maintained stable. As can be seen, the relative humidity changed because of the influence of the ambient temperature during whole segments.  
CO\({}_{2}\), O\({}_{2}\) and C\({}_{2}\)H\({}_{4}\) Concentration Analysis of Fragment Pear Cold Chain Logistics  
The change of CO\({}_{2}\), O\({}_{2}\), and C\({}_{2}\)H\({}_{4}\) for fragrant pear chain from Korla to Beijing is shown in Figure 6. During the ordinary transportation process of fragrant pears, the volume fraction of O\({}_{2}\) declined quickly and the volume fraction of CO\({}_{2}\) inclined quickly in the first segment (transportation). In the second segment (precool) volume fraction of CO\({}_{2}\) decreased gradually from the maximum value of 3.6% and the volume fraction of O\({}_{2}\) increased gradually from 16.6%. In the third segment, both the volume fraction of CO\({}_{2}\) and O\({}_{2}\) varied slightly because fragrant pears were stored at around 0 \({}^{\circ}\)C. In the fourth segment (refrigerated transportation) O\({}_{2}\) concentration varied significantly. There was a significant peak of O\({}_{2}\) concentration, probably the O\({}_{2}\) sensor caused transient misalignment due to prolonged exposure to high relative humidity environment, and CO\({}_{2}\) concentration kept growing in this segment. After the transportation process fragrant pears were temporarily stored in the 5 th segment (sale), and CO\({}_{2}\) concentration increased continually while O\({}_{2}\) concentration was moving in the opposite direction. The level of C\({}_{2}\)H\({}_{4}\) increased sharply to the maximum value (14.1 ppm) in the first segment (transportation) and fluctuated slightly from the second segment (precool) to fifth segment (sale).  
Figure 5: The change of relative humidity in the fragrant pear cold chain.