Organic Compounds in
Food Lab
Purpose: Test samples of food for the
presence of organic molecules using 4
indicators.
 Procedure:
 Materials: 7 food sources, beakers, pipettes,
and 4 indicators:
 Benedict’s Solution – detects glucose
(simple sugar)
 Lugol’s Iodine Solution – detects Starch
(complex sugar)
 Biuret Solution – detects proteins
 Sudan IV – detects lipids (fats)
 Procedures: At lab station
Procedures – At lab station
 1. Demo standards and record results in Data Table 1.
 2. Make predictions.
 3. Place approximately 5 mL of the first food substance in each of
the 4 test tubes.
 Conduct the 4 indicator tests as shown in the demo:
 5 drops of each substance. Benedicts – hot water 5 min
 Record your results in Data Table 2.
 Wash 4 test tubes and repeat with sample 2.
 Repeat the above steps for all 7 substances.
Data Table 1: Standards Test
Substance
Indicator
Used
Color changes
from _____ to
_______
Other
Observation
Glucose
Lipid
Starch
Protein
Data Table 2: Organic Compounds in Food
Food
Lipid Test
Sudan IV
Color
Honey
Egg
White
Potato
Milk
Apple
Juice
Veg. Oil
Corn
Lipids
Present
Carbohydrate Test
Iodine
Color
Starches
Present
Benedict
Color
Protein Test
Glucose
Present
Biuret
Color
Proteins
Present
Conclusion
 1 to 2 paragraphs. Written in 3rd person
(command) form, not in 1st person.
 Discuss your Results:
 Which substances contain lipids, simple sugars,
starch, lipids and proteins?
 How was this determined? Describe the 4 tests
and the qualitative results.
 Discuss any surprising or expected results. Review
your original predictions.
Procedures
 1. Place approximately 5 mL of the first food substance
in each of the 4 test tubes.
 2. Conduct the 4 indicator tests as shown in the demo:
 5 drops of each substance.
 Benedicts should sit in water bath for 5 min.
 3. Record your results in Data Table 2.
 4. Wash 4 test tubes in the sink and repeat with the
remaining 6 samples.