Estimating the calorie content of nuts

LAB EXPERIMENT

CALORIC CONTENT OF FOOD

PURPOSE OF THE EXPERIMENT

The purpose of this experiment was to do a comparison of calorie content of specific foods after determining their energy capacities. This experiment was also done to get to understand calories in detail.

PROCEDURE

Certain foods were weighed and a calorimeter was made in order to determine the weight of the foods. The temperature of the water had initially been calculated, however. The actual weights of pistachio, marshmallow and the chip were determined.

OBSERVATIONS

Data Table 1: Mass of the water

Walnut

Marshmallow

Tortilla chip

Mass of the water (g)

45.8

44.7

49.2

DATA TABLE 2. Caloric Calculations

Food Item Description:

Walnut

Marshmallow (Jumbo)

Other Sample (Chip)

Mass of food, cup and clamp-initial

29.1 g

34.1 g

29.6 g

Mass of food, cup and clamp-final

28.9 g

33.6 g

29.3 g

Mass of burned food

0.2 g

0.5 g

0.25 g

Observation of the Flame (Intensity, length of time burning, etc.)

The pistachio caught on fire so quick and burned for a few minutes

Burned black, but took 8 minutes

The chip caught fire quickly and burned for 60 seconds with a small flame

Water temp- initial (

31.0

28.1

31.1

Water temp- final (

35.6

32.2

35.2

Change in temp () (

4.6

4.1

4.0

(Q) Energy Released (kcal/g)

1.2 kcal/g

0.35 kcal/g

0.8 kcal/g

Energy Estimated on Package (kcal/g)

5.7kcal/g

1.7 kcal/g

5.4 kcal/g

Percent Difference

81 %

80 %

85 %

Determination of Calories according to Atwater Factors (kcal/g)

6.1kcal/g

3.3 kcal/g

5.5 kcal/g

LAB ANSWERS

1. By comparing the calorimeter built with the bomb calorimeter, it is found that they are similar in that both have constant volume and temperature. However, their difference is that the one which was built caught fire outside of water. It was also not enclosed as the bomb calorimeter, and there was no stirring of water.

2. Based on the results, the set up was a good way to measure Calories at home as opposed to a bomb calorimeter. This is because it was easy to make as compared to the bomb calorimeter. An error which might have occurred is heat loss through the tent. If I had unlimited expenses for materials, I would design this set up differently by trying to recreate a real calorimeter rather than a make shift calorimeter.

3. Based on how I burned, the food which would be the best to use for a fuel with a steady flame and might burn for a long time is the chip and pistachio. The chip burned the longest due to its fat content and carb. In the human body, fats and carbs are burned very slowly.

4. Although protein was part of the composition of the foods in this experiment, it was not the main macromolecule component of any of the foods. I think a food consisting primarily of protein was omitted from the tests because proteins are not immediately used as a source of energy as they are stored for later use.

5. The food which had the least amount of Calories per gram was the marshmallow. This is because it had not fat.

6. When the amount of estimated calories was determined, I did not get the same number as what was listed as the amount of Calories per serving on the nutrition level. The discrepancy might have been caused by the rounding up of values by companies when labelling their products.

CONCLUSION

The experiment was quite successful since I learned how to measure and compare calories between foods. I also learned about the effect of calories and specific foods on the human body. The errors in this experiment were as a result of heat loss and inaccurate measurements.