Figuring out the acidic % of a certain food

[chris111]

what's the easiest way to go abouts figuring (using basic lab tools) out the acidic % of a certain type of food, especially if it's a solid not a liquid. Would you still titrate it somehow? Help! please! Thanks

 

[chroot]

What's an "acidic %?" Do you mean pH?

- Warren

 

[ShawnD]

especially if it's a solid not a liquid.

Weigh the food then dissolve it in water. Titrate with very dilute sodium hydroxide.That will tell the number of equivalents. If you know what acid you are looking for (citric in lemons?), you can turn that equivalence into moles, then into mass. Divide the mass of the acid by the mass of the entire thing you dissolved then multiply by 100 and you have % acid.

 

[chris111]

But how would i "Dissolve the item in water"...lets say it's a pickle? Would I just grind it up till its in smaller chunks? Would that be an accurate way? thanks for ur help btw.

 

[GCT]

Acidity in terms of pH pertains to that of an agent's dissociation constant (in relevance to hydronium ions).

As far as the pH of a solid food of any type is concerned, you would simply dissolve the agent in water...if you wish to find the pH of sliced pickels you would do the same, each of them may correspond to different pHs.

If you were concerned about the pH contribution of sliced pickels v.s. larger chunks of these pickels, dissolve both in water and properly calculate pH. The same with any other situation, pH=-log[H30+], each situation will have its own pH.

 

[pack_rat2]

But how would i "Dissolve the item in water"...lets say it's a pickle? Would I just grind it up till its in smaller chunks? Would that be an accurate way? thanks for ur help btw.

I'd pulverize it thoroughly, soak it, then put it in a funnel with filter paper and wash it, collecting the water.

 

[GCT]

In a health perspective this question is somewhat relevant, one with heartburn might want to know the effect of eating a pickel, or rather the contribution of the pickel in further damaging the inner lining of the esophagus (not quite sure about the biology). The straightforward answer would probably be that, the acid component of a pickel is vinegar, thus in don't eat pickels whether sliced, cubed, or in any shape and size.

Thus calculate or look up the pH of vinegar, or try squeezing it out of the pickel, pickel itself is not a compound so you won't determine the pH of it persay.

 

[chris111]

awsome, you guys really know your chem. I was just confused by the whole situation, but that helps a lot! thanks