**4.2 Results and discussions**

During the step 2, one month storing time, the total sugar, the acidity and the soluble solid were measured each two week, and each measurement is an average of six samples. The results were shown in Figure 22 to Figure 24.

From Fig. 22 it can be easily found compared with the referenced group, t the total sugar of Kiwi and pear is higher, which means that a certain thermal process is needed before the cold storage and also means that the method of the ice-temperature is better than the method of cold storage. As for the different cooling processes, the difference is not obvious. But for different fruits, the cooling process plays an important role.

12 12.2 12.4 12.6 12.8 13 13.2 13.4 13.6 13.8 14

KF(-1℃) KS(-1℃) KF(-0.2℃) KS(-0.2℃) referenced group(5.7℃)

mass ratio (%)

0 5 10 15 20 25 30

Fig. 24. Curve of soluble solid vs. time

Table 3: content change after heating

**5. Conclusion** 

total sugar and the soluble solid are affected strongly.

undertaken thermal processions, such as heat and mass transfer of cells.

Heating model

storage time(day)

Before heating

9 9.5 10 10.5 11 11.5 12 12.5 13 13.5 14

PF(-1℃) PS(-1℃) PF(-0.2℃) PS(-0.2℃) referenced gruop(5.7℃)

Total sugar Acidity Soluble solid

After heating

Before heating

mass ratio(%)

(a) soluble solid of kiwi fruit (b) soluble solid of bergamot pear

After heating

Kiwi referenced(5.7ºC) 8.2 10.94 1.15 1.16 12.62 14 Pear referenced (5.7ºC) 6.47 7.35 0.03 0.051 10.4569 10

From Table 3, it can be found that the acidity is not affected by the heating model, but the

The above results were obtained by experiments with little theoretical analysis. In our opinions, the fresh fruits have an ability to adapt to the change of environment. When the fresh fruit is processed by different thermal processing, they will change their inner contents to make them comfortable in a new environment and to prolong their life time liking human being. In future, more works should be paid on thermal action of fresh fruits when they are

Based on the characteristic that fruit and vegetable are living organisms, the ice temperature storage technology of fruit and vegetable enable them to adjust to the cryogenic environment by regulating the precooling process in order to prolong their life period. The ice temperature storage can greatly reduce the metabolic rate, resulting in obvious deviation

KF-S 8.85 9.92 1.27 1.27 12.96 13 KS-S 10.19 10.33 1.31 1.31 13.79 13.5 PF-S 8.64 7.04 0.055 0.055 12.28 11.2 PS-S 7.75 8.62 0.06 0.063 11.72 11.7 KF-F 9.26 9.41 1.28 1.28 13.8 13 KS-F 9.08 10.4 1.32 1.32 12.5 13 PF-F 7.68 7.96 0.051 0.051 11.97 10.8 PS-F 8.69 8 0.096 0.097 11.49 11.5

0 5 10 15 20 25 30

Before heating

storage time(day)

After heating

411

After 30 days in the ice-temperature storage, the total sugar of Kiwi stored in No.1 setup with -1ºC by slow cooling is the highest, while the total sugar of pear stored in No.2 setup with -0.2ºC by slow cooling is the highest.

Fig. 23. Curve of total acidity vs. storage time

From Fig.23-a, it can be found that the acidity of Kiwi first increased with the storage time, and after some days, it reduced. But in Fig. 23-b, the acidity of pear reduced with the time, and after some days, it rose a little. Comparing the different thermal processes in Figure 4, the acidity in the referenced group without any process is the lowest, and the acidity in the group by slow cooing is higher that that of fast cooling. Fig.5 shows the curves of soluble solid vs. time.

In Figure24-a, it can be found that the soluble solid of Kiwi increased with the storage time, but in Fig.24-b it can be found that the soluble solid of Pear increased with the storage time. While we can find that the two fruits processed by fast cooling all have a higher soluble solid. Table.3 shows the content change after different heating model. Table.3 shows the content change after different heating model.

(a) soluble solid of kiwi fruit (b) soluble solid of bergamot pear

Fig. 24. Curve of soluble solid vs. time

After 30 days in the ice-temperature storage, the total sugar of Kiwi stored in No.1 setup with -1ºC by slow cooling is the highest, while the total sugar of pear stored in No.2 setup

> 6 7

> > 0 0.1 0.2 0.3 0.4 0.5 0.6

(a) total sugar of kiwi fruit (b) total sugar of bergamot pear

mass ratio (%)

(a) total acidity of kiwi fruit (b) total acidity of bergamot pear

From Fig.23-a, it can be found that the acidity of Kiwi first increased with the storage time, and after some days, it reduced. But in Fig. 23-b, the acidity of pear reduced with the time, and after some days, it rose a little. Comparing the different thermal processes in Figure 4, the acidity in the referenced group without any process is the lowest, and the acidity in the group by slow cooing is higher that that of fast cooling. Fig.5 shows the curves of soluble

In Figure24-a, it can be found that the soluble solid of Kiwi increased with the storage time, but in Fig.24-b it can be found that the soluble solid of Pear increased with the storage time. While we can find that the two fruits processed by fast cooling all have a higher soluble solid. Table.3 shows the content change after different heating model. Table.3 shows the

0 5 10 15 20 25 30

0 5 10 15 20 25 30

PF(-1℃) PS(-1℃) PF(-0.2℃) PS(-0.2℃) referenced group(5.7℃)

storage time(day)

storage time(day)

8 9 PF(-1℃) PS(-1℃) PF(-0.2℃) PS(-0.2℃) referenced group(5.7℃)

10 11

mass ratio (% )

12

with -0.2ºC by slow cooling is the highest.

KF(-1℃) KS(-1℃) KF(-0.2℃) KS(-0.2℃) referenced group(5.7℃)

KF(-1℃) KS(-1℃) KF(-0.2℃) KS(-0.2℃) referenced group(5.7℃)

0 5 10 15 20 25 30

Fig. 22. Curves of total sugar vs. storage time

0 5 10 15 20 25 30

Fig. 23. Curve of total acidity vs. storage time

content change after different heating model.

storage time(day)

storage time(day)

7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12

1.1 1.15 1.2 1.25 1.3 1.35 1.4 1.45 1.5

solid vs. time.

mass ratio (%)

mass ratio (%)


Table 3: content change after heating

From Table 3, it can be found that the acidity is not affected by the heating model, but the total sugar and the soluble solid are affected strongly.

The above results were obtained by experiments with little theoretical analysis. In our opinions, the fresh fruits have an ability to adapt to the change of environment. When the fresh fruit is processed by different thermal processing, they will change their inner contents to make them comfortable in a new environment and to prolong their life time liking human being. In future, more works should be paid on thermal action of fresh fruits when they are undertaken thermal processions, such as heat and mass transfer of cells.
