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 Glucose Lipid Starch Protein Indicator Used Color changes from _____ to _______ Other Observation

Data Table 2: Organic Compounds in Food Lipid Test Carbohydrate Test Protein Test Sudan IV Color Lipids Present Iodine Color Starches Present Benedict Color Glucose Present Biuret Color Proteins Present Honey Egg White Potato Milk Apple Juice Veg. Oil Corn

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.