I am planning to make a fancy Fruit salad display, but need to prepare it the night b4 so how would I go about preventing the discolouration in them 
No not in water, its not potatoes Malaika :)
After you slice them sprinkle some lemon juice on them. Citric acid is supposed to prevent them from turning dark.
Re: Discoloured Apples.....
Put them apples in an oxygen free environment.
Re: Discoloured Apples.....
Lemon juice, it stops oxidisation. Then cover in clingfilm.
Re: Discoloured Apples.....
ok im gonna give tht a trial run. thnx guys
Re: Discoloured Apples.....
I would cut the apples and put them sprinkle with lemon juice and store them in an air tight box in the fridge, then just mix them in at the last minute.
Re: Discoloured Apples.....
put a bit of lemon juice because u don't want whole thing tasting like lemon and not fruits :) I would say buy press ans seal and put fruit in fridge as TL suggested.
Re: Discoloured Apples.....
drizzle lemon juice over apples........the citric acid in the lemon prevents apples from browning.
Re: Discoloured Apples.....
Along with the lemon juice idea, you can put a little syrup that comes from fruit cans. The prevents any of the fruit from going brown when it's been pre-cut.
Re: Discoloured Apples.....
lemon juice or syrup......use a spray bottle to mix 1 part lemon juice to three or 4 parts water and sprinkle the entire fruit tray.
then cover.
should be fine.
Re: Discoloured Apples.....
try rubbing salt on it .... n u can wash it off later on....
always wrkd for me
Re: Discoloured Apples.....
when u peel them dip in water n vinegar(solution 2 glasses water and 1 tabspn vinegar).when u cut them into pieces just drain the water and use apples...i use this method it s great.