Data Logger

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Data Logger

  1. 1. Bacterial Fermentation AZFATINI BT NAWI D20081032320 ZETY LIYANA BT ZAINALABIDIN D20081032351 SYAFIQAH SHAARI D20091034832 YIP SOOK HAN D20091034841
  2. 2.  Milk is contaminated by bacteria even before it leaves the udder, although at this point they are harmless and few in numbers.  The two main groups of bacteria in milk are Lactic acids and coliforms. Lactic acid is the normal bacteria present in milk and dairy products. Coliforms are the main reason for milk spoilage.
  3. 3. Before After 1 day What happen to the milk? Why?
  4. 4. Planning and Doing Experiment – observation of the change in pH when the milk is left for 1 day.
  5. 5. Result Time (hour) pH Time (hour) pH 1 5.442 13 5.186 2 5.442 14 5.174 3 5.442 15 5.158 4 5.380 16 5.149 5 5.360 17 5.142 6 5.340 18 5.133 7 5.299 19 5.121 8 5.278 20 5.117 9 5.258 21 5.112 10 5.237 22 5.096 11 5.230 23 5.074 12 5.197 24 5.063
  6. 6. Graph 4.8 4.9 5 5.1 5.2 5.3 5.4 5.5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 pH Time (hour) pH versus Time (hour) pH
  7. 7. Discussion 1. Did you see a reduction of pH shortly after starting the experiment? 2. What causes the reduction in the pH of milk? 3. Does the speed of change in pH stay constant over the whole experiment period? 4. Calculate the extent of change in pH obtained in the process. 5. What would be the results of incubating UHT milk over the same time period?
  8. 8. School Milk Program has to be postponed for a time being because the food poisoning case among students due to milk spoilage. What are the factors causing the milk spoilage and how to overcome the problems?
  9. 9. By using data logger, we do not need a constant observation. The graph can be plotted easily. Low cost because we only use milk. The result can be analyzed and interpreted easily. Easy to perform.
  10. 10. Measuring the pH of Milk. Retrieved on 31st August 2010 from http://www.picotech.com/experiments/ph_ of_milk/ph_of-milk.html

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