THE MORE THE MERRIER Bacterial Fermentation GROUP 6 AZFATINI BT NAWI D20081032320 ZETY LIYANA BT ZAINAL ABIDIN D20081032351 SYAFIQAH SHAARI D20091034832 YIP SOOK HAN D20091034841
SCIENTIFIC CONCEPT 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.
ENGAGE Before After 1 day What happen to the milk? Why?
ENGAGE Planning and Doing Experiment – observation of the change in pH when the milk is left for 1 day.
EMPOWER Discussion Did you see a reduction of pH shortly after starting the experiment? What causes the reduction in the pH of milk? Does the speed of change in pH stay constant over the whole experiment period? Calculate the extent of change in pH obtained in the process. What would be the results of incubating UHT milk over the same time period?
ENHANCE 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?
UNIQUE FEATURES Low costbecause we only use milk. Easy to perform. By using data logger, we do not need a constant observation. The graph can be plotted easily. The result can be analyzed and interpreted easily.
REFERENCE Measuring the pH of Milk. Retrieved on 31st August 2010 from http://www.picotech.com/experiments/ph_of_milk/ph_of-milk.html