How to recognize difference between real and fake cold drinks?

[Knoxy]

Hi!

 

I'm a 18 year old guy living in India and persuing my graduation in Biology.. I have a bad experience last night..

 

And I'm sorry for the incorrect English as its my second language..

 

Here goes the story?

 

Last night I was in a celebration of my friend's b'day and there were two bottles of pepsi present there.. One is sealed pack pepsi (1L in plastic bottle) and another one is 300 ML in glass bottle...

 

When I drink both of them I found that there was lots of difference among both.. The glass bottle one was seems to be fake as it was too much bitter and having a foul smell in it.. Much similar to smell of contaminated water..

 

I'm sure that pepsi is not real one and thousands of such fake cold drinks are sold over here per day.. This could lead various diseases in general public..

 

What I want?

 

I want to test the difference between the pepsi in both bottles and want to figure it out what harmful substances does it actually contain?

 

I will then show my reports to media and newspaper companies and they can spread a mass awareness against this..

 

I hope you geniuses will help me through out this..

 

I'm doing my graduation in Biology and also have chemistry as main subject throughout all semesters.. I'm allowed to conduct testing for the product in lab..

 

Suggestion welcome..

[PaulS1950]

I would start with the basics - PH tests, specific gravity and then see if I could find a collaborator who would run a spectragraph to compare the chemical make up of the two liquids.

The problem I foresee is how to determine which bottles have been tampered with - some may be genuine.