Energy Value in Food
Transcript of Energy Value in Food
Energy value in
food samples.....
.EXPERIMENT 6.1
AIM
• To determine the energy value in food samples.
PROBLEM STATEMENT
• What is the energy value of different food samples?
HYPOTHESIS
• The energy values of different food samples are different.
VARIABLES
• Manipulated variable: food samples
• Constant variable : volume of water
• Responding variable: energy value of food samples
MATERIALS
• Distilled water, food sample (groundnut, green bean, flour) and plasticine.
APPARATUS
•A thermometer, a boiling tube, a retort stand and clamp, a pin, an electronic balance, wind shield and a Bunsen burner
TECHNIQUE
• Calorimetry- measuring of the amount of heat released in its combustion.
PROCEDURE
• 1. 10ml of water (mass=10 g) is poured into a boiling tube and the boiling tube is clamped to the retort stand in an upright position.
• 2. a small piece of food is weighed and recorded.
• 3. the initial temperature of the water in the boiling tube is recorded.
• 4. the food is fixed at the end of the mounted pin.
• 5. the food is burned using the Bunsen burner.
• 6. as soon as the food burns, hold it about 1cm below the boiling tube.
• 7. the water in the boiling tube is stirred with a thermometer and the temperature rise is recorded when the food stops burning.
• 8. the boiling tube is emptied and refilled with another 10ml of water.
• 9. repeat steps 1 – 8 using a different food sample each time.
• 10. the energy value of food is calculated with the following formula:
• Energy value= mass of water (g) x temperature rise (oC)
x 4.2J/goC• mass of food (g)
measurement
Types of foods
groundnut green bean
flour
Mass/g 0.33 0.1 5
Initial temperature/oC
29 29 29
Final temperature/oC
44 31 45
Change in temperature/oC
15 2 16
Energy value (J/g)
1909 840 134.4
CONCLUSION
• Experimental results show that groundnut, green bean and flour have different food values.
• Decision: hypothesis is accepted