Food and Nutrition in Humans : Food and Nutrition in Humans Food Test and Storage
Food Test theory : Food Test theory Heat is required ONLY for Benedict’s test for reducing and non-reducing sugars
Reducing sugars are so called because they reduce blue copper sulphate (CuSO4) in Benedict’s solution to a reddish precipitate
Food Test theory cont’d : Food Test theory cont’d Simple sugars are reducing sugars
Some complex sugars are also reducing sugars e.g. maltose
Sucrose, a complex sugar is a non-reducing sugar
Food Test theory cont’d : Food Test theory cont’d There is no direct test for non-reducing sugars
A non-reducing sugar can be broken down to simple sugars by heating it with a dilute acid like HCl (hydrolysis)
The resulting mixture is acidic and must first be neutralized by adding a small amount of alkali like NaHCO3
The test for reducing sugar can then be carried out
The red precipitate obtained confirms that a non-reducing sugar was originally present
Table summarizing the method and results of food tests : Table summarizing the method and results of food tests
Complete the following table to indicate where and in what forms the named organisms store food : Complete the following table to indicate where and in what forms the named organisms store food
Complete the blank spaces in the following tale which shows the method and positive results of selected food tests : Complete the blank spaces in the following tale which shows the method and positive results of selected food tests
Essay Type : Essay Type (a) State clearly how you would test a sample of flour for
(b) Include the apparatus and materials you would use
(c) Describe the procedure and the results expected if positive
Starch
Reducing Sugar
Protein
Fat
Slide 9 :
FOOD RESERVES AND SITES OF STORAGE IN SOME COMMON SEEDS : FOOD RESERVES AND SITES OF STORAGE IN SOME COMMON SEEDS