Calculating bone percentage from calcium content?

Hi Catsite,

I found finely ground beef (with bones) at the butcher's. They can tell the calcium content of the product, but don't have its bone percentage. I need its bone percentage because I use frankenprey's 80/10/5/5 ratio as a general guide. Could someone help me calculate the bone percentage of this ground beef using its calcium content?

My butchers have these two produtcs.

ground chicken wings

It contains calcium 15000mg/kg according to the butcher.

Roughly 46% bone as it is made of chicken wings.

ground beef (with bones)   ← what I want!

It contains calcium 5900mg/kg according to the butcher.

Roughly ?% bone.

As they can't tell which part of beef they use (it may change depending on seasons,) I can't tell this product's bone percentage. I only have its calcium content.

So I assumed I could use this ratio:

15000mg : 46% = 5900mg : x%

(GCW calcium : GCW bone percentage = GB calcium : GB bone percentage)

x=18

This product seems to be roughly 18% bone.

Am I right about this bone percentage, or using calcium : bone ratio in calculation? Or am I wrong?

Can I calculate the bone ratios of any other ground beef products if other butchers have similar ones?

Thanks!   

I would ask your butcher how they have determined the calcium content. With the ground chicken wings I can see how they *might* have had a lab analyse a batch and then just used that analysis for all their chicken wing batches since they use the same ingredient for each batch. But for the beef, if they use different beef parts depending on what they have available how do they know they have a consistent calcium content? I find it hard to believe they would get an analysis of each batch. But maybe they get that information from their supplier???

I'm also not a fan of using the calcium content of one type of bone and assuming it is representative of all bones. The bone in chicken wings in particular don't seem very comparable to what would be in chicken thighs for instance.  The thigh would be a weight bearing bone and so would be more dense than what is found in a wing. 

I can't say for sure that there is anything wrong with what you have suggested but I'm not at all sure I would be comfortable with it.

Thanks for your advice, mschauer!

I see, so I can't assume bones from chickens and cattle are similar and that's where I was wrong. I didn't take it into consideration when I tried to calculate, but the bone composition of humans (and probably many other animals) is much different from that of birds as birds must fly. I think the calcium contents were also very different because birds have porous bones (though I can't seem to find the source I read). It'd be natural if cattle and cows have a different bone composition than chickens'. So I can't really apply the same ratio to both of them.

And yes, I will definitely ask the butcher how they know the product's calcium content! Guess we should use this product only sparingly even then, as it sounds like the product isn't likely to have a consistent nutrient profile.

Thanks again for your reply!