TO TEST FOODS FOR STARCH. 21 



5. Pour a small amount of iodine into a test- 



tube of water. What do you observe? 



6. Put a small amount of grape-sugar into a 



test-tube; into a second test-tube some 

 white of egg mixed with water ; and into 

 a third tube put some mutton tallow 

 (fat). "Add a little iodine to each. 



a. Do you notice any change in the color 



of any of the substances? 



b. Do any of the colors resemble at all 



the change of color resulting from 

 the addition of iodine to starch? 



7. From the preceding experiments state how 



you can determine whether a substance 

 contains much starch, little starch, or no 

 starch. 

 B. Application of iodine test to various foods. 



1. Test as many foods as you can by adding 



hot water to a small amount of each on 

 a white butter-dish or saucer, and then 

 applying iodine (e.g., oatmeal, flour, raw 

 meat, egg, milk, parsnip, potato, onions, 

 apples (both green and ripe), beans, rice, 

 pepper). 



2. Tabulate your results in columns under the 



following heads : 



