Confirmation of presence of food components in Food Component – Class 7 Science Experiment
Chapter Name: Food Component
Activity Name: Confirmation of presence of food components in Food Component
Activity Description:
In this experiment, we aim to confirm the presence of specific food components in various food materials. Specifically, we will test for the presence of starch in different food items.
Starch is a common carbohydrate found in many foods, and we can detect it using a dilute iodine solution. When iodine reacts with starch, it forms a characteristic dark-blue or black color, indicating the presence of starch.
Required Items:
- Different types of food materials (e.g., milk, a potato, a bit of oil/ghee)
- Test tubes or plates
- Test tube stand
- Dropper
- Iodine solution
- Water
Step by Step Procedure:
- Preparation of Dilute Iodine Solution: a. Take a test tube or a cup. b. Add a few drops of iodine solution to it. c. Dilute the iodine solution with water until it becomes light yellow/brown.
- Testing for Starch: a. Take a sample of each food item in separate test tubes or on a plate. b. Using a dropper, add a few drops of the prepared dilute iodine solution to each food sample.
- Observation: Observe the color change in each food sample after adding the iodine solution.
- If the substance turns dark-blue or black, it indicates the presence of starch in that food item.
Experiment Observations:
- Milk:
- Observation: After adding the dilute iodine solution to the milk sample, there was no significant color change. The milk sample retained its original color, showing no indication of the presence of starch.
- Potato:
- Observation: When the dilute iodine solution was added to the potato sample, the color of the solution changed to a dark-blue/black. This color change indicates the presence of starch in the potato.
- Oil/Ghee:
- Observation: No change in color was observed in the oil/ghee sample after adding the dilute iodine solution. The solution remained its light yellow/brown color, indicating the absence of starch in the oil/ghee sample.
Precautions:
- Use separate test tubes or plates for each food item to avoid contamination of samples.
- Be careful while handling iodine solution as it can stain skin and clothing. If any spills occur, clean them up immediately.
- Do not taste or consume any of the food samples used in the experiment, as they might be contaminated with chemicals.
Lesson Learnt from Experiment:
Through this experiment, we can confirm the presence of starch in different food items. Starch is a vital source of energy for our bodies, and its presence in various food materials can be an essential indicator of their nutritional content.
This simple test allows us to identify starch-containing foods, which can be valuable information for dietary considerations and understanding the composition of different food items.
