border=0


Calculation of energy value (calorie content) of food




Energy value is the amount of energy released in the body during the oxidation of proteins, fats and carbohydrates contained in the product. To determine the theoretical caloric value, for example, 100 g of a food product, it is necessary to calorie nutrients (1 g of fat releases 9 kcal, 1 g of protein - 4 kcal and 1 g of carbohydrates - 3.75 kcal) multiplied by the percentage of the corresponding nutrients.

The sum of the products obtained is the theoretical calorie content of 100 g of food product. Knowing the calorie content of 100 g of the product, you can determine the calorie content of any quantity (300 g, 1 kg, etc.). Knowing the theoretical energy value (calorie content) of, for example, carbohydrates, one can find their practical (actual) energy value by multiplying the result of the theoretical calorie content of carbohydrates by digestibility in percent (for proteins - 84.5%, fats - 94, carbohydrates - 95.6%) and dividing the resulting work by 100.

Practical exercises

Using the data in table. 3, determine the theoretical and practical calorie content of 200 g of the product (on the instructions of the teacher).

Table 3. The chemical composition of individual products per 100 g of product,%

Option Number Products Squirrels Carbohydrates Fats Water Ash
Sour cream 20% 2,8 3.2 20,0 72.7 0.5
Pasteurized milk 2,8 4.7 3.2 88.5 0.7
Meat pork 14.5 - 33.0 51.6 0.8
Category I beef 18.9 - 12,4 67.7 1,0
Dairy sausages 12.6 - 25.3 60.0 2,4
Rafinated sugar - 99.9 - 0.1 -
Potatoes 2.0 19.7 0.1 75.0 1,1
The apples 0.4 11.3 - 86.5 0.5
Eggs 12.7 0.7 11.5 74.0 1,0
Fat cottage cheese 14.0 1.3 18.0 64.7 1,0

Task example

Example. Determine the theoretical and practical energy value of 100 g of wheat flour (in kcal and kJ), which includes 10% protein, 2% fat, 60% starch .

Decision. Energy value is expressed in kilocalories (kcal) or in the system in kilojoules (kJ). 1 kcal = 4.18 to J.

3.75 kcal of energy or 15.7 kJ is released per 100 g of the product during the oxidation of 1 g of carbohydrates; 1 g of protein - 4 kcal (16.7 kJ) of energy and 1 g of fat - 9 kcal (37, 7 kJ) of energy.

Theoretical energy value of 100 g of wheat flour is:

E.c. 100 g = 10 * 4 + 2 * 9 + 60 * 3.75 = 283 kcal

E.c. 100 g = 10 * 16.7 + 2 * 37.7 + 60 * 15.7 = 1185.4 kJ.

The practical energy value of 100 g of wheat flour is:

E.c. 100 g = 10 * 4 * 0.845 + 2 * 9 * 0.94 + 60 * 3.75 * 0.956 = 267.8 kcal


border=0


E.c. 100 g = 10 * 16.7 * 0.845 + 2 * 37.7 * 0.94 + 60 * 15.7 * 0.956 = 1112.6 kJ.





; Date Added: 2015-10-22 ; ; views: 42772 ; Does published material infringe copyright? | | Personal Data Protection | ORDER JOB


Did not find what you were looking for? Use the search:

Best sayings: When passing the laboratory work, the student pretends that he knows everything; the teacher pretends to believe him. 9205 - | 7262 - or read everything ...

Read also:

border=0
2019 @ edubook.icu

Page generation in: 0.002 sec.