A YEAR IN SCIENCE 103 



Each foodstuff shows certain definite qualities by 

 which its presence may be detected. 



Exercise 69. Tests for Foodstuffs. 

 Object: To determine a test for protein, starch, 

 sugar, fat and oil. 



Apparatus 



Cornstarch Grape sugar 



Ammonia Egg-white 



Benzine and ether Mutton tallow 



Vnglazed paper Ground flax seed 



Test tubes Iodine 



Evaporating dish Fehling's solution 



Filter paper Nitric acid 



Bunsen burner Hydrochloric acid 

 Stirring rod 



Directions: A. Test for starch: Place a small 

 amount of cornstarch in a test tube. Add water and 

 shake the mixture. Does the starch dissolve? (To 

 answer this question compare this mixture with a 

 solution of salt and water.) Boil the mixture. What 

 hange do you note? Dip the end of a glass stirring 

 rod into the paste. Over the paste on the glass rod 

 pour a few drops of iodine. What is the result? 



B. Test for grape sugar : Place a small amount of 

 grape sugar in a test tube and add enough water to 

 dissolve it. What is the difference in the effect of 



at(M- on sugar and starch? Add a few drops of 

 Fehling's solution and boil. What change do you 

 To a solution of cane sugar add Fehling's 



