1 / 8

Chemical indicators

Chemical indicators. How to detect macromolecules in food. What is a chemical indicator?. A substance that changes to indicate that a specific compound is in what you’re testing. The change can be color, temperature, odor, or production of bubbles. They are VERY specific!

knaack
Download Presentation

Chemical indicators

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Chemical indicators How to detect macromolecules in food

  2. What is a chemical indicator? • A substance that changes to indicate that a specific compound is in what you’re testing. • The change can be color, temperature, odor, or production of bubbles. • They are VERY specific! • Easiest to use is color usually.

  3. Indicators we will use • Benedict’s Solution • Lugol’s Iodine • Biuret Solution • Sudan IV

  4. Benedict’s Solution • Used to test for monosaccharides • Normally light blue color • Mix it with your food, then heat it up • Change of color to green, yellow, orange, or red indicates monosaccharide is present greenorange red brown

  5. Lugol’s Iodine • Used to test for polysaccharide starch • Normally yellow to light brown in color • Mix with your food • Change of color to dark purple or black indicates starch is present

  6. Biuret Solution • Used to test for proteins • Normally light blue in color • Mix with food • Change of color to purple (light to dark range) indicates presence of a protein

  7. Sudan IV • Used to test for lipids, specifically fats • Normally red in color • Mix with equal parts food and water • A red-stained oil layer will separate out and float on the water surface if fat is present

  8. Procedure • First you need to perform the tests on control so that you know what a positive test looks like • Then test on unknown foods • Some foods will have more than one type of macromolecule

More Related