Mr. T's Science Scene

Nutrient Testing

Fast and Easy Tests

Protein Test:

1.  Place all your samples on a plate or petri dish.  Make sure they do not touch.

2.  Put 1-3 drops of BIURET'S SOLUTION on each sample.  Be careful:  Biuret's is a medium acid which will cause itching on the skin.


Positive Color/Result:  Purple or Lavender

Negative Color/Result:  (Stays the same color- light blue)


Notes:  This can be a hard test to evaluate becuase meat is typically dark and you can't see the color change.  Remember:  all protein products come from animals in one way or another.  You also need to leave the chemicla on for a minute or so.


Starch Test:

1.  Place all your samples on a plate or petri dish.  Make sure they do not touch.

2.  Put 1 drop of IODINE on each sample.  Be careful:  This will stain your clothing and not come out!


Positive Color/Result:  Black or a dark purpleish

Negative Color/Result:  (Stays the same color- amber/yellow/rust)


Notes:  If the sample has starch the change will be immediate.


Longer Tests

Fat/Lipid Test:  DO THIS FIRST!!!!

1. Get a foot of paper towel and put your name on it.

2.  Draw a circle for each of your samples and number them according to your data table sheet.

3.  Take each sample and smudge/stain/squish the sample onto the paper towel IN the appropriate circle leaving a stain and NOTHING MORE.  If your sample is dry, add water to make a paste and squish that on.  There should be no food samples on the paper towel.

4.  Put a little water on the edge/corner of your towel.  (This is a timer)

5.  Put your towel with the stains on it under the warm, bright lights.  The water will evaporate.

6.  When the water has evaporated and the towel is dry, the test is done!


Positive Color/Result:  The circle (with the sample stain) looks wet, greasy, or translucent.

Negative Color/Result:  The circle (with the sample stain) looks dry and is not translucent.


Sugar Test:

1.  Be Careful.  Hot plates and hot liquid.

2.  You will need all test tubes for this. . . Number them 1-whatever amount of samples you have.

3.  Put each of your samples into a test tube (according to your key on the data sheet) and add water so that it just covers your sample.

4.  Add BENEDICT'S SOLUTION to each test tube so that the water/sample is blue/blueish.

5.  Put (all) test tubes into a beaker of hot water and wait 2-3 minutes.

6.  Remove them, note color changes, and clean them out for the next person.


Positive Color/Result:  Green (little sugar), Yellow (medium sugar), Orange (lots of sugar)

Negative Color/Result:  (Stays the same color- blueish)


Notes: Be careful and observe all safety precautions.


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