The Caloric Content of Food
Experimental Report
AT(T) = Tr (°C) — CC) Temperature change:
(Equation 2)
Calculate the change in temperature (as shown in Equation 2 above) of the water °I each combusted food item and report this difference in Table 1.
Cheetos
Protein Puffs
Baked Puffs
Food Cheetos Puffs Heat released (in calories I g) Heat released per g (in Food Calories) Expected Food Calories from Macronutrients Percent Error (%) Protein Puffs Baked Puffs
3. In your calculation, you assumed that all the heat released by the combusted food item was absorbed by the water. Do you think this is true or not? If it is not true, would this tend to make your estimated calories too big or too small?
4. The night shift nurse at Northside hospital administers 255 mL of an IV solution of glucose whose concentration is 5.00 % m/V ( 5.00 g glucose in 100 mL solution). Calculate the kilocalories of energy that is provided to this patient. Carbohydrate – 4 kcal/g Fat – 9 kcal/g
Protein – 4 kcal/g
1. Using information on the nutrition label of the food sample, calculate the Cal/gram. (Divide Calories per serving by the number of grams in a serving.) Report this quantity (in Food Calories) in Column 3 of Table 2.
lEx-perunentall’alue—ExpectedValuei Percent Error (%) = x 100 Expected Value
(Equation 3)
2. Calculate the percent error (use Equation 3 above) [(Column 3 – Column2)/(Column 3)*100]. Report this percentage in Column 4 of Table 2.
Cheetos
Protein Puffs
Convert the scientific calories above in Column 1 of Table 2 into food Calories and report this value in Column 2 of Table 2. 1 Cal (food) = 1000 cal (scientific) = 1 kcal (scientific).
Protein Puffs
Baked Puffs
Divide the energy calculated above for each food sample by the corresponding mass of food consumed (Table 1). This provides the heat released per gram of food. Record this energy value (in calories / g) in Table 2, Column 1.
Cheetos
Protein Puffs
Baked Puffs
Table 1: Water temperature before and after food combustion
Food Mass of Water for each sample (g) Mass of Food Sample + Stand (g) Ti (°C) Tf (°C) C AT (°C) Mass of Burned Sample + Stand (g) Mass of Food y 1 Consumed(g) Cheetos Puffs Protein Puffs Baked Puffs
Heat Calculation: Using the temperature change (AT) and mass of water from Table 1, and the specific heat capacity of water (1.00 cal/WC) and Equation 1, determine the quantity of heat (q) released by combusting each food. Note this is the same as heat absorbed by water.
Cheetos
Protein Puffs
Calculate the change in mass (as shown in Equation 3 above) of the food item and report this difference in Table 1.
Cheetos
Protein Puffs
Baked Puffs
Table 1: Water temperature before and after food combustion
