B2 - Food tests Flashcards
How would you test for carbohydrates?
Add Benedict’s reagent to food and BOIL in water bath
How can you carry out a test for carbohydrates properly?
Boil the sample.
What is the initial colour of Benedict’s solution?
Blue
What will happen if carbohydrates are not present in the sample?
It’ll stay blue.
What will happen if carbohydrates are present in the sample?
It’ll turn brick red.
How would you test for starch?
Add iodine reagent to food
What is the initial colour of iodine?
Brown/orange
What will happen if starch is present in the sample?
It’ll turn blue black
What will happen if starch is not present in the sample?
It’ll stay brown/orange
How would you test for protein?
Add Biuret reagent to food
What is the initial colour of Biuret reagent?
Blue
What colour will the sample turn if protein is present?
Lilac/purple
How would you test for fat (lipids)?
Add ethanol to the food to dissolve the fat then add water
What will happen to the sample if fat is not present?
It will stay colourless
What will happen if fat is present in the sample?
White emulsion.