international baccalaureate group 4 project presentation_milk by felix dyrek
TRANSCRIPT
CATTLE’S MILK
Group V
Felix Dyrek
INTRODUCTION
• Our experiment was about investigating the pH of the FRESH COW MILK during 7 days. We have made 3 samples of this milk and have put them to test tubes. Each sample was put to: fridge (temperature 2C), heater ( temperature 35C) and to the place with room temperature 20C. Each day we were checking those pH at two periods of time – at 09:00 and 15:00.
Functions of milk
Cow's milk may indeed be the all time great miracle food since it provides us with:
• the basic vitamins: B, B12, D, K, K1 – better health and energy production
• iodine– important component of thyroid functions(metabolism)
• calcium – strong bones• proteins – human body relies on them• selenium – important in metabolism and immune functions• biotin and pantothenic acid – metabolic functions• nutrients - strong healthy body and mind. • probiotics – protects against a variety of infectious
diseases.
Smells bad but no visual changes
515:00
Smells bad but no visual changes
509:00
04.03.2008
Smells bad but no visual changes
515:00
Smells bad but no visual changes
509:00
03.03.2008
Smells bad but no visual changes
515:00
Smells bad but no visual changes
509:00
29.02.2008
No visual, chemical changes.
5-615:00
No visual, chemical changes.
5-609:00
28.02.2008
No visual, chemical changes.
615:00
Fresh cow milk609:00
27.02.2008
OBSERVATIONS[2oC] / pHHOURDATE
Bad smell is very intensive, milk has yellow colour, water appered on the
bottom of the test tube
415:00
Bad smell is very intensive, milk has yellow colour, water appered on the
bottom of the test tube
409:00
04.03.2008
Bad smell is very intensive, milk has yellow colour, water appered on the
bottom of the test tube
515:00
Bad smell is very intensive, milk has yellow colour, water appered on the
bottom of the test tube
509:00
03.03.2008
Smells bad ,milk has yellow colour515:00
Smells bad ,milk has yellow colour509:00
29.02.2008
Smells bad ,no visual changes5-615:00
Smells bad ,no visual changes5-609:00
28.02.2008
No visual, chemical changes615:00
Frsh milk609:00
27.02.2008
OBSERVATIONS[20 oC] / pHHOURDATE
pH decreased, bad smell is still very intensive, upper layer is solid, yellow, loads of sediment are occupying test-
tube’s walls
415:00
pH decreased, bad smell is still very intensive, upper layer is solid, yellow, loads of sediment are occupying test-
tube’s walls
409:00
04.03.2008
Bad smell is very intensive, water starts to appear on the surface of upper part which became solid. Some sediment
appeared on walls of test tube.
4-515:00
Bad smell is very intensive, water starts to appear on the surface of upper part which became solid
4-509:00
03.03.2008
Milk smells badly, upper part becomes solid and turns yellowish
515:00
pH changed, milk starts to smell bad509:00
29.02.2008
No visual or chemical changes5-615:00
No visual or chemical changes5-609:00
28.02.2008
No visual or chemical changes615:00
Milk is fresh and liquid form609:00
27.02.2008
OBSERVATIONS[35 oC] / pHHOURDATE
We can observe how cow milk is acting after leaving it in those three tepmeratures. Starting from the heater ( temperature 35°C) we can observe that because of hot tempreature reaction of fermentation of cattle’s milk was the fastest and the strongest. It is the first sample which reached pH 4 and it happened after 6 days.In the room temperature this process was a little bit slower. It needed one more day to get pH 4. It is connected woth temperature of course because fermentation of milk comes mucha faster when the temperature is increasing.The third sample was put to the fridge with temperature 2°C. We can observe that thanks to the temperature which was the slowest the process of fermentation was also slower and never got the level of pH 4 but finished at 5.
CONCLUSIONS
Photos of test tubes with milk during our observations
Fridge (2ºC)
Room (20ºC) Heater (35ºC)