# To determine the amount of energy in different foods and to find out how much this depends on the fat content of the food.

Biology Coursework        Jaspreet Athwal 10P/10D2

Burning Foods Investigation

Aim: To determine the amount of energy in different foods and to find out how much this depends on the fat content of the food.

Introduction

Most foods contain fats, carbohydrates and proteins, usually in a mixture. These are all organic molecules, which contain energy. This investigation looks at the amount of energy in six different foods. Energy values are measured by burning the foods underneath a boiling tube containing a fixed volume of water. The temperature rise in the water can be used to calculate the energy values in the water.

Energy released from food (J) =mass of water (G) x temperature rise (°C) x 4.2

If you divide this value by the mass of the food, you get a fair comparison.

Equipment

• Test tubes
• Mounting needle
• Retort stand with clamp
• Bunsen burner
• Thermometer
• Water

Method

• Gather equipment, test tubes, Bunsen burner, foods and retort stand.
• Pour exactly 15cm³ of room temperature water into the test tube.
• Clamp the test tube using the retort stand and place thermometer inside.
• Record the temperature of water.
• Find the mass of the food and record.
• Place the food onto a mounted needle.
• Place over the Bunsen burner until it catches fire.
• Place directly under test tube until it cannot set alight anymore.
• Take the temperature of water and record.
• Calculate the energy (see above).
• Repeat with other foods.

[To compare results, energy per gram needs to be calculated.

Energy released from food (in J/ G) =energy in the food (from

Formula above) weight (g)]

The independent variable is the rise in temperature of the water. I will take the temperature before the experiment. I will then take the temperature after the experiment.

Diagram

Safety Precautions

Goggles must be worn to protect the eyes from spitting of food when alight and incase test tube breaks due to the heat from the Bunsen burner.

You should be standing whilst performing the experiment just incase the Bunsen burner should drop.

How will the ...