Lab #2: McMush
What’s in a Happy Meal?
The food you eat provides your body with energy and other substances necessary to carry on life
activities. Compounds such as carbohydrates, proteins, and fats are present in the plants and
animals you use as food. Vitamins and other minerals are obtained from food as well. In this lab,
you will learn how to test for specific compounds and then use those tests to determine if the
compounds are present in a fast food meal. Just what is in a fast food meal??
PURPOSE: In this lab activity, you will…
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
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Identify the reagents used to test for the presence of
certain organic and inorganic compounds and observe
positive test results.
Identify the organic and inorganic compounds found in a
fast food meal
In the activity below, you will learn how to test for the
following compounds: proteins, sugar, starch, vitamin C,
salt and fats. Then in Part II, you will apply that knowledge
to testing for the presence of the same compounds in a
McDonald’s Happy Meal.
BACKGROUND INFORMATION:
 The four most important kinds of organic compounds in living things are carbohydrates,
lipids, proteins and nucleic acids. All of these compounds are found in the food we eat.
 The cells in all living things contain these organic compounds as well as nucleic acids
(another macromolecule) and inorganic compounds such as vitamins and minerals.
 Carbohydrate molecules include simple sugars, double sugars and starches, which are the
preferred energy sources for most organisms.
 Lipids are fats and oils that function in long term energy storage and in the structure of cell
membranes. Proteins may be structural molecules such as those that form muscles.
 Organic compounds present in foods can be analyzed using reagents such as Biuret,
Sudan III, Benedict’s solution, and iodine.
 Inorganic compounds, such as salt and Vitamin C, which are also present in foods, can be
analyzed using reagents such as silver nitrate and indophenol solution.
Materials:
Test Tubes
Distilled Water
Benedict’s Solution
Starch Solution
Indophenol solution
Oil
Gelatin Solution
Beaker
Hot Plate
Lugol’s Iodine Solution
Salt Solution
Sudan III
Biuret Solution
Glucose Solution
Test Tube Clamps
Vitamin C Solution
Silver Nitrate Solution
McMush Solution
Part I: Testing of Known Substances
Protein test
1. Place 5 mL of the gelatin solution into one of your test tubes (Test Tube 1).
2. Place 5 mL of distilled water into another test tube (Test Tube 2).
3. Add 1 mL of Biuret solution to each test tube.
4. Observe and record any color change.
Glucose test
1. Place 5 mL of the glucose solution into a clean test tube (Test Tube 1).
2. Place 5 mL of distilled water into another clean test tube (Test
Tube 2).
3. Add 3 ml of Benedict's solution to each test tube. Place the tube in
a beaker of boiling water and boil for five minutes. Use test tube
clamps to take the hot test tubes out of the water bath at the end of
the five minutes.
4. Observe and record any color change.
Starch test
1. Place 5 mL of the starch solution into a clean test tube (Test Tube
1).
2. Place 5 mL of distilled water into another clean test tube (Test Tube 2).
3. Add 5 drops of Lugol's iodine solution to each test tube.
4. Observe and record any color change.
Vitamin C test
1. Place 5 mLof the vitamin C solution into a clean test tube (Test Tube 1).
2. Place 5 mL of distilled water into another clean test tube (Test Tube 2).
3. Add 5 drops of indophenol solution to each test tube.
4. Observe and record any color change.
Chloride test
1. Place 5 mL of the salt solution into a clean test tube. (Test Tube 1)
2. Place 5 mL of distilled water into another test tube. (Test Tube 2)
3. Add 5 drops of silver nitrate solution to each test tube.
4. Observe and record any color change.
Fats Test
1. Place 10 mL of water in test tube #1.
2. Place 10 mL of oil in test tube #2.
3. Add 10 drops of Sudan III in each of the test tubes. Set the tubes aside for 30 minutes.
4. Carefully examine and describe the results.
Record your results in Table 1:
Table 1: Results of Food Nutrient Tests
Food Substance
Reagent test
Test Tube 1
Results
Test Tube 2
Results
Gelatin
Glucose
Starch
Vitamin C
Sodium chloride
Fat
Part II: McMush
Your teacher will place the Happy Meal in a blender and blend until an emulsion is prepared. The
emulsion will then be filtered, and you will receive some of the resulting solution.
1. Predict the substances that you expect to find in the McMush solution in Table 2.
2. Record your predictions in the data table using a “+” or a “-“. Include the part(s)
of the meal that you believe will contain that particular nutrient.
Table 2: McMush Predictions and Results
Food Substance
Prediction and from what part
of the meal
Actual Results
Protein
Sugar
Starch
Vitamin C
Sodium Chloride
Fat
3. Repeat the reagent tests above using 5 ml of the McMush solution for each test. except for the
sodium test, where you will use 2 ml of filtered McMush solution).. Make sure you use clean
test tubes for each test
4. Describe and record your results in Table 3.
Food Substance
Protein
Reagent test
Biuret solution
Sugar
Benedict's solution
Starch
Lugol's iodine solution
Lipid
Brown Bag
Sodium
Silver nitrate
Test Results
ANALYSIS QUESTIONS:
1. What was the purpose of the distilled water test tube for each of the nutrient tests from
Part 1?
2. List the reagents, and the positive tests for the nutrients in Part 2.
Protein:
Glucose:
Starch:
Vitamin C:
NaCl:
3.
Describe the reasons for your predictions in Part 2 in the spaces below. (For example, “I/we
predicted that protein would/would not be in the McMush because I/we think that
_____________________contains protein”.)
Protein:
Glucose:
Starch:
Vitamin C:
NaCl:
4. How did your predictions compare with your actual results in Part 2?
5.
How would you determine which part of the meal contained each nutrient?
6.
Go to the following site and follow the on-line instructions for the meal builder to build your Happy
Meal (Sprite, Cheeseburger and French Fries):
http://www.mcdonalds.com/us/en/meal_builder.html#
In Part 2, you only tested for the presence of the nutrients, not the relative amounts –
are your results supported by the nutrition information supplied by McDonald’s? Explain.
7. How does the presence of fat that you observed compare to the Total Fat % given on the web site?
8. Compare your Happy Meal % nutrients to the % daily value; you may assume that an average daily
calorie requirement is 2000 calories, and an average daily protein intake is 40 grams. Do you
believe that a Happy Meal can be part of a balanced diet? Explain your answer.
Conclusion: As you write you conclusion, don’t forget to include the following:
 The purpose of the lab.
 How to test for each compound present in food, including positive results.
 What compounds are present in a McDonald’s Happy Meal.
 Whether a McDonald’s Happy Meal can be considered nutritionally balanced, with
data to support your decision.
 Recommendations for changes in the menu based on your findings.