Flour is the finely ground meal of wheat or other cereal grains. But we can’t eat it raw.
Things Required:
1 tablespoonful of sugar
1 tablespoonful of flour
2 glasses half full of cold water
Directions:
Stir the sugar into one of the glasses of cold water.
Stir the flour into the other glass of cold water.
This Is What Happens:
The sugar disappears. The flour does not.
Science Behind It:
The sugar dissolves in the water. The grains of flour are too big to dissolve. When you stir the flour and water together, you get a paste in which each grain is hanging suspended in the water.
When you chew your food-but before you swallow it-saliva works to help you digest it. Sugar molecules separate and mix with saliva immediately.
Flour, however, is suspended in the saliva, just as it is in the glass of water. The tough wall of plant cells around each grain of flour prevents the starch molecules from getting out. Nothing can get in unless the wall is broken-neither water was needed to soften the starch nor the enzymes that would digest it. Heat breaks that wall. That’s why flour needs to be cooked.
