Bomb Calorimetry
What is Bomb Calorimetry?
Procedure:
The freeze dried sample was weighed and milled, using the Wiley Mill. Dried ice was fed into the machine to keep the sample cool. Then the milled sample was divided into four individual bottles, to be used for future assays. This will help protect the sample from microbial growth during unfreezing and refreezing. After the sample returned to room temperature, two samples of approximately 0.6 grams were weighed and a pellet press was used to create a pellet for the bomb calorimeter. After the pellet was created, the two samples were weighed to determine a more precise weight, to input into the calorimeter. The calorimeter was set up (pre-test and standardized with a benzoate acid tablet) for the reaction and the calories per gram was determined for each sample.
Additional Information: |
Bomb Calorimetry is a process that measures the heat combustion of a ~1 gram sample* to determine the calorie per gram value.
*Note: the sample MUST be dried prior to use for bomb calorimetry . Bomb Calorimeter: an apparatus that measures the heat combustion of a sample enclosed in a steel bomb,which is surrounded by water and located in a controlled environment. The following is a list of the various features (which can be viewed in the image on the left) found in a typical bomb calorimeter and a brief description of some features:
If you are interested in observing the actual burning of food to measure caloric content, please watch this YouTube video.
Refer HERE for more information on bomb calorimetry
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Purpose of Experiment:
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To determine the caloric content of the Chef Boyardee Lasagna sample through the use of a bomb calorimeter
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Results:
Sample 1: 4501.5855 calories/gram Sample 2: 4508.1448 calories/gram
= 262.83 kilocalories (dry weight) =263.18 kilocalories (dry weight)
Experimental Sample: Actual Sample:
-Average: 263.01 kilocalories per 256.34 grams -250 kilocalories per 249 grams-Actual Sample:
= 262.83 kilocalories (dry weight) =263.18 kilocalories (dry weight)
Experimental Sample: Actual Sample:
-Average: 263.01 kilocalories per 256.34 grams -250 kilocalories per 249 grams-Actual Sample:
Discussion/ Implications:
The bomb calorimetry results, of calories per gram, and the calculated kilocalories for both samples indicate that 0.5809 grams of the sample has 2.6150 Calories and 0.5954 grams of the sample contained 2.6841 Calories. Although the samples differ in weight by only about one hundredth of a gram, this seemingly slight variation results in a difference of multiple hundredths in kilocalories. The first sample had 2.6150 kilocalories, while the second sample had 2.6841 kilocalories, with a difference of 0.0691 kilocalories. This provides an average of 2.650 kilocalories.
In comparison to the nutrition facts label, regarding the kilocalories, the numbers are relatively similar. The first sample had a kilocalorie value of 262.83, while the second sample had a kilocalorie value of 263.18. The average of the two samples is 263.01 kilocalories. The nutrition facts label for the sample indicates a kilocalorie value of 250. The percent difference between the actual and expected value is 5.07%, suggesting that this difference in kilocalories is not too severe.
In comparison to the nutrition facts label, regarding the kilocalories, the numbers are relatively similar. The first sample had a kilocalorie value of 262.83, while the second sample had a kilocalorie value of 263.18. The average of the two samples is 263.01 kilocalories. The nutrition facts label for the sample indicates a kilocalorie value of 250. The percent difference between the actual and expected value is 5.07%, suggesting that this difference in kilocalories is not too severe.