| MadSci Network: Agricultural Sciences |
The leaf should be ground up in water that contains 1% hydrochloric acid [also sold as muratic acid], filtered through cloth and boiled 5 minutes. This process hydrolyzes the sucrose to glucose and fructose [its component sugars]. Using a standard of glucose obtained from the college, make up a series of dilutions to determine where a diabetic test strip [available at pharmacies], gives the best reaction/ sensitivity to your defined concentrations of glucose.
Once you know the best range of sensitivity, dilute the plant sample to generate a dilution that gives a good reaction on the diabetic urine test strip and compare the dilutions of standard and sample to determine concentration of glucose in the plant [= unknown].
Starch can be hydroyzed with spit - saliva contains a enzyme that breaks down starch to glucose, to be absorbed in digestion. Incubate the spit and plant extract overnight at room temperature then test in the same way as above. It is important to test untreated [control] extracts to determine the change a treatment causes to the sample. Compare your untreated samples with the treated ones to measure the extent of any differences.
Good luck!
Jack Paxton,
Professor Emeritus, Dept. Crop Science
Univ. of Illinois