A food sample comprise 2.0g protein, 1.0g fat, 4.0 Carbohydrate. what is the Energy contributed by Fat alone in joule and Kilocal?

 

It is rarely measured as just fat alone. You would find the heat of combustion.

what if there is a standard Calorie equivalents for 1g of these nutrient?

Hardly there are many types of fats. Each with their own heat of combustion.

Hardly there are many types of fats. Each with their own heat of combustion.

Not really. They are all very similar.

All fats give about 9 Calories per gram.

Edited November 22, 201411 yr by John Cuthber

All fats give about 9 calories per gram.

 

How do you even know that?

Anyway I didn't know how they extracted the fat from food so I looked it up.https://www.apsu.edu/sites/apsu.edu/files/chemistry/SP11_1021_DETERMINING_HOW_MUCH_FAT_IS_IN_FOOD.pdf

They find the percentage of fat by mass in a number of samples and take an average.

Edited November 22, 201411 yr by fiveworlds

How do you even know that?

Anyway I didn't know how they extracted the fat from food so I looked it up.https://www.apsu.edu/sites/apsu.edu/files/chemistry/SP11_1021_DETERMINING_HOW_MUCH_FAT_IS_IN_FOOD.pdf

I know it because I read a lot.

I assume from what you said that you did not know it.

Since you didn't know it, and you have just implied that you wouldn't expect to know it,

why did you post a reply that is wrong and where you knew that you didn't have any understanding of the issues?

Incidentally,I suspect that this sort of thing is more commonly used to measure fat in food these days.

 

http://www.oxford-instruments.com/OxfordInstruments/media/industrial-analysis/magnetic-resonance-pdfs/Using-Nuclear-Magnetic-Resonance-to-Test-Fat-Content-in-Foods.pdf

Edited November 22, 201411 yr by John Cuthber

I know it because I read a lot.

 

Oh right I read lots too http://books.google.ie/books?id=zIq9UBNQOskC&pg=PA53&lpg=PA53&dq=heat+combustion+of+fats+chemistry&source=bl&ots=cdqcl3SqYe&sig=FNOoqYFzD-n_mOP_Vu8sesPAzM4&hl=en&sa=X&ei=BZ5wVKySConuaObDgrgD&redir_esc=y#v=onepage&q=heat%20combustion%20of%20fats%20chemistry&f=false