Food Test Flashcards
What is the food test for reducing sugars and describe it.
The Benedict’s test- 2cm3 (cube) of the solution to be tested is placed in a test tube. 2cm3(cube) of Benedict’s solution is then added. The mixture is shaken and then brought to a gentle boil.
The initial blue color will turn green then yellow and may form a brick red precipitate .
What is the food test for starch and describe it.
2cm3(cube) of 1% starch solution is added to a test tube. A few drops of iodine in potassium iodide solution is added. It results in a blue black precipitate.
What is the food test for proteins and describe it.
Biuret test- 2cm3(cube) of protein solution is placed in a test tube. 2cm3(cube) of 5% potassium hydroxide is added. The mixture is stired and 2 drops of 1% copper sulfate is added. A purple color slowly develops.
What is the food test for fats and describe it.
Ethanol test- 2cm3(cube) of fats solution or oil is added in a test tube. 2cm3(cube) of absolute ethanol is then added. The mixture is shaken vigorously and then 3cm3(cube) of water is added. A cloudy white suspension can be seen when the water is added.
