How an investigation could be carried out to compare the effect of storage time on the vitamin c content of the Parana' state Camu-Camu fruit with those from the Amazon region?

This is a core Practical in the edExcel Biology AS level, I will explain everything in steps :

1) fill a burette with 1% vitamin c solution

2) using a syringe measure 5ml of DCPIP and squirt into conical

3)collect a white tile and a conical flask and by using the burette pour the 1% vitamin c solution drop by drop into the conical flask and shake

4)the DCPIP should turn pink then colourless if right amount of drops has been added.

5)repeat process with the two different camu-camu juice

6)take results and work out averages

These are the basic steps to the practical and on an exam question like this one it's best to include as much detail in summarized points. :)