Friday 24 June 2011

Final experiment - data

9. How to show that the experimentation was carried out as reported? (Evidence) Use of photograph, audio or video recording.


 

Orange juice samples in room temperature. (31 degrees Celsius)

Orange juice samples in the fridge. (8 degrees Celsius)


10. How to organize and present the data collected? (Results)
1st experiment
Initial pH level of orange juice samples: 3.48
Elapsed Time (hours)
pH Level of Covered Orange Juice Sample in Fridge (8°C)
pH Level of Exposed Orange Juice Sample in Fridge (8°C)
pH Level of Covered Orange Juice Sample in Room Temperature (31°C)
pH Level of Exposed Orange Juice Sample in Room Temperature (31°C)
0
3.48
3.48
3.48
3.48
¼
3.48
3.49
3.48
3.49
½
3.49
3.52
3.50
3.54
¾
3.51
3.54
3.52
3.58
1
3.53
3.56
3.55
3.61
1¼ 
3.56
3.60
3.56
3.65
3.57
3.65
3.58
3.69
3.58
3.68
3.60
3.72
2
3.60
3.71
3.63
3.77
3.61
3.73
3.64
3.79
3.64
3.77
3.66
3.83
3.66
3.81
3.70
3.86
3
3.67
3.82
3.74
3.89



Initial pH level
pH level at the end of 3h
Change in pH level
Percentage of change in pH (%)
Sample of covered orange juice in fridge
3.48
3.67
+0.19
+5.46
Sample of exposed orange juice in fridge
3.48
3.82
+0.34
+9.77
Sample of covered orange juice in room temperature
3.48
3.74
+0.26
+7.47
Sample of exposed orange juice in room temperature
3.48
3.89
+0.41
+11.8

2nd experiment
Initial pH level of orange juice samples: 3.32
Elapsed Time (hours)
pH Level of Covered Orange Juice Sample in Fridge (8°C)
pH Level of Exposed Orange Juice Sample in Fridge (8°C)
pH Level of Covered Orange Juice Sample in Room Temperature (31°C)
pH Level of Exposed Orange Juice Sample in Room Temperature (31°C)
0
3.32
3.32
3.32
3.32
¼
3.32
3.33
3.33
3.33
½
3.34
3.35
3.35
3.36
¾
3.36
3.38
3.36
3.41
1
3.37
3.40
3.38
3.44
1¼ 
3.40
3.44
3.41
3.48
3.42
3.46
3.44
3.53
3.43
3.50
3.46
3.57
2
3.45
3.55
3.47
3.62
3.46
3.59
3.50
3.65
3.47
3.63
3.54
3.70
3.49
3.67
3.58
3.74
3
3.52
3.69
3.61
3.80



Initial pH level
pH level at the end of 3h
Change in pH level
Percentage of change in pH (%)
Sample of covered orange juice in fridge
3.32
3.52
+0.20
+6.02
Sample of exposed orange juice in fridge
3.32
3.69
+0.37
+11.1
Sample of covered orange juice in room temperature
3.32
3.61
+0.29
+8.73
Sample of exposed orange juice in room temperature
3.32
3.80
+0.48
+14.5

11. What do the data mean? (Data Analysis)
From both experiments, we can see that the pH of all four samples of orange juice increase over time. However, the pH of the two exposed samples of orange juice increase at a faster rate than the two covered samples of orange juice. There is also a greater change (increase) in pH levels of the exposed samples of orange juice at the end of 3 hours compared to the covered samples. In the first experiment, the exposed sample of orange juice in room temperature experienced 4.33% more increase in pH than the covered sample in room temperature. Likewise, the exposed sample in the fridge had a 4.31% more increase in pH than the covered sample in the fridge.

The pH level was also affected by the difference in temperature. The orange juice samples placed in the fridge were kept at 8°C while the samples outside in room temperature were kept at 31°C for 3 hours concurrently. From both experiments, we can see that the pH level of the orange juice samples out in room temperature increase at a faster rate than the orange juice samples in the fridge. There is also a greater change (increase) in pH levels of the samples in room temperature at the end of 3 hours compared to the samples in the fridge. In the second experiment, the covered sample of orange juice in room temperature had a 2.71% more increase in pH than the covered sample in the fridge. Likewise, the exposed sample in room temperature increased 3.4% more in pH compared to the exposed orange juice sample in the fridge.

This increase in pH level shows the rate at which the vitamin C content in the orange juice is degrading. This shows that vitamin C degrades faster in orange juice when the juice is exposed to air and when it is stored in warmer temperatures. Also, since there were no other affecting factors to the change in pH level of the orange juice aside from exposure to air and storage temperature, and the experiment was repeated to achieved similar results, it is safe to say that it is fairly accurate.

12. What can you deduce from the discussion of your data analysis? (Conclusion)
With this set of data, I can deduce that exposure to air affects the degradation of vitamin C in orange juice. The more the exposure to air, the faster the rate of degradation of vitamin C in orange juice. This also means that the lesser the orange juice is exposed to air, the better the retention of vitamin C. I can also deduce that different storage temperatures affect the degradation of vitamin C in orange juice. The higher the temperature the orange juice is stored in, the faster the rate of degradation of the vitamin C content in the juice. This also means that the lower the temperature, the better the retention of vitamin C in orange juice.

Therefore I can then prove that it is best to store orange juice without exposure to surrounding air and in cold temperatures (to minimize the degradation of vitamin C, shown by the change in pH). This then proves my hypothesis right.


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