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Created by Elena Cade
over 9 years ago
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Question | Answer |
Name the food test for Reducing Sugars (Glucose, Fructose, Maltose etc.) | Reducing Sugar Test (Benedict's Reagent) |
How would you prepare this test? | 1) Dissolve food sample in water 2) Equal volume of Benedict's reagent added 3) Heated in water bath Colour change from blue-green-yellow-brown-red shows positive result... stays blue if negative |
Name the food test used for Protein: | Biuret test |
How would you prepare this test? | 1) small amount of food in test tube 2) add 2ml of Biuret solution A purple or violet colour shows a positive test, stays blue if negative. The presence of peptide bonds is indicated by the solution going purple |
What food test would you use for a fat/lipid: | Emulsion test |
How would you prepare this test? | 1) small amount of food in tube 2) 2ml ethanol added 3) pour the ethanol off into another tube 4) add a little water and shake gently A milky colouring shows a positive test |
What food test would you use for starch: | Starch test |
How would you prepare this test? | 1) small amount of food in test tube 2) 2 drops of potassium iodide Blue-black colouring shows positive test stays yellow if negative |
Name the test used for Non-Reducing Sugar (sucrose): | Non-Reducing Sugar test/ Benedict's Reagent |
How would you prepare this test? | 1) Check there is no reducing sugar by heating part of the sample with benedict's R 2) Hydrolyse the rest of the sample by heating with dilute hydrochloric acid 3) test sample again with B-R Orange-Red precipitate formed if positive result |
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