An agricultural scientist investigated the rate of microbial decomposition in three different organic food preparations (Mango purée, Melon purée, and Coconut water) at various temperatures. They measured the time taken (in days) for the pH of each preparation to drop to 4.0 as an indicator of decomposition.
The results of the investigation are shown in the graph below.
a.[1]
Which organic food preparation remains fresh (takes the longest to reach pH 4.0) the longest at 15 ∘C15\ ^\circ\text{C}15 ∘C?
b.[2]
Describe the effect of temperature on the time taken for Mango purée to reach pH 4.0. Use values from the graph in your answer.
c.[2]
Suggest reasons why Melon purée decays faster at 25 ∘C25\ ^\circ\text{C}25 ∘C than at 15 ∘C15\ ^\circ\text{C}15 ∘C.