Experiments you can do at home!
Want to see taste, flavor, and/or spit in action? Try these.
Pudding and spit
AKA: Don't double dip... we'll know.
Get a pudding cup--or make pudding (must be the kind made with starch or flour of some sort, not egg-based). Take a bite of pudding. Swish it around your mouth for 15 seconds, then spit it back into the pudding cup.
Stir for 1 minute. Compare your pudding to a friend or family members.
Don't see anything? Let the pudding sit for 5 minutes.
By now, you should notice the pudding is much more liquid than it was at the beginning. This is caused by "salivary alpha-amylase"--which is a molecule in your spit that chops up starch into smaller pieces. As the starch gets smaller, the pudding becomes less thick. The little bitty pieces of starch can more easily slide past each other than the long chains of starch, which were tangled together and made the thicker gel structure in the original pudding.
If you do the experiment with a friend, you may notice that your cups of pudding liquify at VERY different speeds. Some people's spit will liquify the pudding in seconds, others take minutes. This is something our lab is studying!
Redox reactions... that you can see, and smell!
Get some paprika and make some popcorn. Use plenty of oil or butter!
Sprinkle the paprika generously over the popcorn. Shake/stir/mix, until the popcorn is orange. The orange comes from the carotenoids in the popcorn!
Separate the popcorn into a few different cups, take a picture, and stash the cups in places with different light and temperature conditions. We chose the freezer, a dark cupboard, and sunny window.
Wait a few days. Then take a look--compare the color of the popcorn in the different environments. Is one less orange than the others? Now smell the popcorns. Do you notice a difference in odor between the popcorn that kept its color and the ones that lose the orange color?
You probably will! That smell is "lipid oxidation"--one of the ways that fat goes rancid. In the picture of our experiment, the popcorn from the sunny window (which is whiter after a few days) smelled old and dirty, like a french fry you find under you car seat a few months later. The more orange ones, which are less oxidized, still smelled like... well, popcorn! (we don't recommend you eat it, though, after it sat out a few days...)