Name Melanie Black-Van Wright
Partner if applicable
Observations of formation of casein precipitate
The milk began to curd. As the curd increases the milk appeared more clear at times.
Mass of casein
Observation of CuSO4 biuret Test
Test Results (+ or -)
Solution turned violet
Egg white solution turned violet
Water solution turned blue
Sugar solution turned blue
1. Whas is the theoretical yield of casein based on the table of Milk Composition Analysis?
2. What is your percent yield? 3.2g/3.9g x 100= 82%
3. Why might your percent yield be lower than expected?
More fat has a decrease in protein which would cause a lower percent yield.
4. Why might your percent yield be higher than expected? Less fat causes an increase in protein, thus giving a higher percent yield.
5. In the precipitation of casein, why is it important that the temperature be maintained at 40°C?
To allow and encourage , for example with the milk casein to form and appear.