Science Buddies: "Ask an Expert"

Hi
I am doing science fair project on measuring the fructose in different drinks like coke gatorade and frutis like pineapple grape and orange juice. I havent figured out a way to measure the fructose yet. I need help on how to measure the fructose and i researched online but i couldnt find any ways to measure so can you guys help me figure out a way to measure the fructose. My project is due on Feb 26. Thanks

Hi,

If you have access to a spectrophotometer in a college or university lab, you can use the following kit to measure fructose in food: http://www.sigmaaldrich.com/catalog/pro ... &region=US

All the other methods for fructose measurement that i know of would require access to a lab, analytical instruments and experience in chemistry. The anthrone assay is a very common assay for sugars, but it requires the use of concentrated sulfuric acid.

The only way I can think of for simply estimating the fructose content of your various drinks would be to buy some fructose and make a series of standards of known concentration--say 1%, 5%, 10% and so on, and use these to estimate the sweetness of the drinks. You would have to get some volunteers to drink one of the beverages then to taste fructose solutions, beginning with the lowest concentration, until they found the one that they thought was closest to the sweetness of the drink.

Sweetness is not perceived the same by everyone, so actually it would be interesting to compare the sweetness estimates of several people to one beverage by comparing it to your standards. If you tested 5 or more people, you could do a statistical analysis on the data. You could try comparing cola, apple juice and sweetened tea with your fructose standards and see how many of your test subjects [the more the better!] agreed on the sweetness level. You might be surprised at the results.

I hope this helps since i know your deadline is coming up fast.

Good luck!

Sybee