Questions and Answers
What color change indicates the presence of starch in a food item?
Which solution is added to test for proteins?
What observation indicates the presence of fats in a food test?
What is the major nutrient that includes starch and sugars?
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Which nutrient is not a macronutrient found in food?
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Study Notes
Major Nutrients in Food
- Primary nutrients include carbohydrates, proteins, fats, vitamins, and minerals.
- Dietary fibers and water are also essential parts of food.
Testing for Starch
- Dilute iodine solution: made by adding iodine tincture to water.
- Copper sulphate solution: prepared by dissolving 2 g in 100 mL of water.
- For testing, apply 2-3 drops of iodine solution to the food sample.
- Color change to blue-black indicates the presence of starch.
Testing for Proteins
- For solid food, grind into a powder before testing.
- Combine powdered food with distilled water in a test tube and shake.
- Add two drops each of sodium hydroxide and copper sulphate solutions.
- A purplish color confirms the presence of proteins.
Testing for Fats
- Similarly, powder solid food before testing.
- Mix powdered food with 2-3 mL of ethanol in a test tube and shake.
- Decant the clear solution and add 2-3 mL of water, then gently shake.
- Formation of whitish globules on the water's surface indicates the presence of fats.
Safety Precautions
- Avoid tasting or eating any chemicals during testing.
- Exercise caution while conducting experiments to ensure safety.
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Description
Explore the essential nutrients found in food, including carbohydrates, proteins, and fats. This quiz also delves into various testing methods for identifying starch, proteins, and fats in food samples. Test your knowledge on these fundamental concepts.