Chemical Forums
Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: michaelwants2grow on November 19, 2020, 07:49:39 AM
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So my final undergraduate project involves me finding the calorie content of typical drinks consumed in my country (fruit juice, carbonated drinks, beers, wines, etc.) and comparing it to the one found on the nutrition label. The methods i saw involved me calculating the fat, protein and carbohydrate content individually, but i would be repeat testing over 20 drinks and that seemed pretty difficult so i wanted to inquire about the other feasible methods, that i can carry out as an undergraduate and preferably not too expensive and with a spectrophotometer being involved?
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For one it depends on how accurate you need to be. If you are willing to assume that, for example, the overwhelming source of calories in soda is sugar, then you can just determine the amount of sugar and go from there.
For instance, if I wanted to determine the amount of calories in Coke, I would take a can of Coke, boil off the water in a tared container, find the residue mass, assume it is all sugar, convert to calories using the typical formula for number of calories per gram of sugar. This would give a decent estimate. If you wanted something more precise, you could boil off the contents, then determine the actual calorie count of the residue by calorimetry.
This doesn't quite work for alcoholic beverages because the alcohol boils off, but there are ways to determine alcohol content.
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You have to be careful with boiling coke, I tried it once and the sugar started degrading so I was left with much less than what was stated on the bottle.
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Good point, I guess "remove the water under reduced pressure" would have been a better suggestion.
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i wanted to inquire about the other feasible methods, that i can carry out as an undergraduate and preferably not too expensive and with a spectrophotometer being involved?
Are you saying you would like inexpensive methods and it is OK to use a spectrophotometer, or that you don't want to use spectrophotometry?
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i wanted to inquire about the other feasible methods, that i can carry out as an undergraduate and preferably not too expensive and with a spectrophotometer being involved?
Are you saying you would like inexpensive methods and it is OK to use a spectrophotometer, or that you don't want to use spectrophotometry?
It is okay to use a spectrophotometer, i wanted to know if there were any reagent tests possible or so
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For one it depends on how accurate you need to be. If you are willing to assume that, for example, the overwhelming source of calories in soda is sugar, then you can just determine the amount of sugar and go from there.
For instance, if I wanted to determine the amount of calories in Coke, I would take a can of Coke, boil off the water in a tared container, find the residue mass, assume it is all sugar, convert to calories using the typical formula for number of calories per gram of sugar. This would give a decent estimate. If you wanted something more precise, you could boil off the contents, then determine the actual calorie count of the residue by calorimetry.
This doesn't quite work for alcoholic beverages because the alcohol boils off, but there are ways to determine alcohol content.
I assume for certain beverages i can just boil off