add benedicts reagent ( blue ) to a sample and heat it in a water bath thats set to 75 degrees , if the sugars are present it will form a coloured precipitate , the higher the concentration , the further the colour will change
how does the colour change based on reducing sugar concentration
blue,green,yellow,orange,brick red
how do you test for starch
add iodine solution to a test sample , if starch is present , the sample changes from a browny orange to a dark blue-black colour , if there is no starch , it says browny orange
how do you test for lipids
emulsion test , shake the test substance with ethanol for about a minute until it dissolves, then pour the solution into water , if there any lipids , they will precipitate out and show up as a milky emulsion , the more lipid there is , the more noticeable the milky colour will be
how do you test for protein
add a few drops of potassium hydroxide to the solution to make it alkali , then add some copper sulfate sulfate solution which is bright blue , if theres no protein , the solution will stay blue , if the protein is present , the solution will turn purple
