food tests

• What is the test for starch?

  The iodine test.
• What is a summary of the iodine test?

  Adding a few drops of iodine solution to the food.
• What is the result is iodine is present?

  The iodine will change from orange to blue-black.
• What is the test for sugars?

  The Benedict's reagent test.
• What is the method for the Benedict's test?

  • Adding the reagent to the sample.
  • Heating it at over 80 degrees for 3 minutes.
• What is the result is glucose is present?

  Colour change from blue to green/yellow/orange or brick red.
• What is the test for proteins.

  The biuret reagent test.
• What is the method for the biuret test?

  Adding the reagent to the sample.
• What is the result if there is protein present?

  A colour change from blue - to lilac.
• What is the test for lipids?

  The ethanol test.
• What is the method of the ethanol test?

  • Adding 1cm cubed of ethanol to the food and putting the liquid from the food into water.
• What is the result from the ethanol test if ethanol is present?

  The water changes from clear to cloudy.