Required Practical 10 - Investigate the effects of temperature on the rate of decay of fresh milk by measuring pH change.

Question 1

Method to investigate the effects of temperature on the rate of decay of fresh milk by measuring pH change:

Answer 1

1) Make a solution of milk and phenolphthalein indicator
2) Add sodium carbonate which will cause the solution to become alkaline and therefore appear pink
3) Place the tube in a water bath as a specific temperature
4) Add the lipase enzyme and begin stopwatch
5) Time how long it takes for the pink colour to disappear /9i.e. when the pH has decreases)
6) Repeat this at different temperatures to see at which temperature the pink colour disappears the quickest, indicating the quickest decomposition