A student investigated how temperature affects the decay of different milks. During decomposition, lactic acid bacteria break down carbohydrates in the milk to produce organic acids, which lowers the pH of the milk.
The student measured the time taken (in hours) for whole milk, soy milk, and oat milk to reach pH 4.5 at different temperatures. Their results are shown in the graph below.
Which type of milk remains fresh for the longest period of time at 15 ∘C15\ ^\circ\text{C}15 ∘C?
Describe the effect of temperature on the time taken for whole milk to reach pH 4.5. Use data from the graph in your answer.
The time taken for soy milk to reach pH 4.5 at 25 ∘C25\ ^\circ\text{C}25 ∘C is less than at 15 ∘C15\ ^\circ\text{C}15 ∘C. Suggest one reason why.