|MadSci Network: Chemistry|
A food chemist determines the amount in moisture in a food product by drying a weighed sample until it looses all its water. To do this you need a sensitive scale for weighing the sample (popcorn in this case) before and after drying it. For example if you take 100 grams of popcorn (that's about ½ cup) and place it on a flat pan in a heated oven, it will start to lose water. You can tell the water is evaporating because the corn will lose weight. Good popcorn is 10 to 13% water, so it will finally weigh only about 87 to 90 grams. The technique is to take the popcorn from the oven and weigh it every 3-4 hours, and when two successive weights are the same you have evaporated all the water and you can calculate the original water content. Popcorn that loses even a little water will not pop very well. People who have worked with popcorn sometimes recommend adding some water back to dried-out popcorn to make it pop again. Put 2-3 cups dry popcorn kernels in a quart jar and add from 1-2 tablespoons of water and shake the popcorn to wet it evenly. Let it set a few hours and try to pop a few kernels. If it still does not pop you might add few more drops of water and wait longer for it to re-hydrate. (Be careful not to pour water in hot oil as it can spatter and burn your skin.) Below are some websites where you can learn more about popcorn. Marion Ohio even has a popcorn museum at http://www.wyandotpopcornmus.com/ Another site dedicated to popcorn is http://www.popcorn.org/ Phyllis Phyllis J. Stumbo, PhD, RD, LD, firstname.lastname@example.org Clinical Research Center, University of Iowa, Iowa City, IA 52242 Office (319) 384-9746 FAX (319) 384-8325
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