H. FOOD MATERIALS AND HOW TO DETECT 

 THEM 



Nutrients 



A nutrient is a chemical compound capable of nourishing 

 the body. Foods are good for us because they contain one 

 or more of these chemical compounds. 



The nutrients are proteins, carbohydrates, fats and oils, 

 water, and mineral salts. 



Proteins always contain carbon, hydrogen, oxygen, and 

 nitrogen, and they may also contain a few other elements, 

 such as sulphur, phosphorus, iron, etc. Since they all 

 contain nitrogen, they are often known as nitrogenous foods. 



Carbohydrates are mostly composed of carbon, oxygen, 

 and hydrogen. Sugars and starches are the principal carbo- 

 hydrates. Fats and oils are rich in carbon and hydrogen. 



Water forms a large part of most foods. Common salt 

 is the principal mineral salt entering, into food, but there 

 are also compounds of lime, sulphur, phosphorus, and many 

 other elements in various articles of diet. 



The following experiments will teach how to detect the 

 presence of various nutrients in any kind of food. 



7. PROTEIN 



Object. To learn how to detect the presence of protein 

 in food. 



Apparatus. White of egg, lean meat, nitric acid, ammonia, 

 Millon's reagent, biuret reagent, lamp, and test tubes. 



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