3rd Grade Science Experiment

We read about carnivorous plants like the pitcher plant and venus flytrap in our "ScienceWorld" magazines.  We learned that they dissolve their food.  Then we conducted an experiment to see how different substances dissolve starches (specifically a Saltine cracker).  We crushed a dime-sized amount of Saltine into three different cups.  Then added our substances: dish soap, pineapple juice, and water. We let it sit for 10 minutes.  Then we added a drop of iodine to each cup.  The iodine turns black when it comes into contact with starch, so we could tell which substances had dissolved the starch.  Many of us made the hypothesis that the pineapple juice would dissolve the most starch, but it turns out we were wrong.  The iodine did not react at all in the dish soap, so it did not have any starch left.  The iodine turned really black in the water, so it did not dissolve the starch at all.