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If you have some sort of sports drink that contains sucrose, how would you take that sucrose and break it down into its components, glucose and fructose? I know that sucrose + water will break it apart, but how can it still remain together (as sucrose) while in the bottle of sports drink?

I am trying to compare the levels of glucose in various sport drinks. So I'm planning to use Benedict's solution and a spectroscope in order to determine the amount of glucose present in solution (I'm going to add activated charcoal to the solution to remove the colouring from it before placing in the spectroscope).

I will prepare standards by adding 5 grams of glucose to 100 mL of water, 10 grams of glucose to 100 mL water, and so on.

As a high school student I only have limited resources. Any information about my proposed plan or alternatives that are low-cost are appreciated.

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    $\begingroup$ Is eating it allowed? That will certainly work. Only issue is that you can't get back the glucose + fructose. $\endgroup$ – orthocresol Sep 15 '16 at 10:59
  • $\begingroup$ I know this is a stab in the dark and you may or may not have even done this experiment, however, I am in high school and by coincidence happen to be doing this exact experiment. What method did you go for in the end and how did it work out? Did you manage to get the results you wanted? Really appreciate any help! $\endgroup$ – Ben Porter Feb 9 '17 at 22:55
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Sounds like a great experiment!

As you state, a sucrose solution in water eventually hydrolyzes to fructose and glucose, but without a catalyst, the reaction rate is extremely slow; beverages are stable at room temperature for years. However it is hydrolyzed in hours at room temperature by adding sucrase enzyme (secreted in the small intestine), invertase enzyme (derived from yeast) or even a weak acid such as citric acid, tartaric acid, or even dilute hydrochloric acid.

You may need to test whichever of these are available for compatibility with Benedict's solution, though, and you may need to test some of the other ingredients in the drinks to see if they also cause false positive otr negative effects. You might compare the results from the Benedict's test with those from a blood-sugar glucometer (the solutions may need to be diluted in both tests to stay within a measurable range).

BTW, study of yeast fermentation of sucrose is responsible for the name enzyme, meaning leavened with yeast, so one could say invertase is the epitome of an enzyme.

Please share your experimental results here.

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