Tests for food Flashcards
iodine test is for?
starch
how to test for iodine?
put food in test tube. add few drops of iodine solution to food using a pipette. if it turns from brown to blue- black starch is present.
what colour does iodine solution if starch is present.
blue to black
what is benedict’s test for?
reducing sugars
how to test for reducing sugars?
add equal volume of benedict’s solution to food. place in hot water bath for a few mins. reducing sugars are present a brick red precipitate is formed. if its absent stays blue
What colour does benedict’s solution go if reducing sugars are present?
Brick red
Test to see if protein is present?
Biuret’s reagent
How to test for proteins?
add few drops of biurets reagent to food sample in test tube. shake and wait a few mins. if proteins present it turns from blue to purple.
What colour does biuret solution go if protein is present?
Purple
Test to see if lipids are pressent
add ethanol to food sample. pour this mix in test tube of equal volumes to distilled water. if lipids are present, a while emulsion is formed
What is the name to see if proteins are present?
emulsion test
What colour does the emulsion test go if lipids are present?
White/ cloudy
