“Open Thread”

Too tired to do a real post at the moment. I’ve seen other bloggers do this “Open Thread” thing, inviting readers to post comments about whatever the heck they want so as to make the blog look more active without actually having to post anything. So what the heck. Real post in the next 24 hours hopefully, but in the meantime, what’s on everyone’s minds?

Oh, yeah, and am I right that typical cola drinks are about 3 mM phosphate (as phosphoric acid)?

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The Author is (currently) an autodidactic student of Industrial and Environmental microbiology, who is sick of people assuming all microbiology should be medical in nature, and who would really like to be allowed to go to graduate school one of these days now that he's finished his BS in Microbiology (with a bonus AS in Chemistry). He also enjoys exploring the Big Room (the one with the really high blue ceiling and big light that tracks from one side to the other every day) and looking at its contents from unusual mental angles.

6 thoughts on ““Open Thread””

  1. I think the phosphoric acid has been implicated (and I have seen no empirical support for or against the idea, maybe because I haven’t looked) in chemically-induced bone loss in people who drink an assload of diet cola. My gut feeling is that such people are more likely to have low calcium intake to begin with — diet-soda fans often eat like finches across the board — and that the soda habit is an indirect and nonspecific marker.

    Well, you did say to just run our mouths.

  2. I’ve heard the “phosphoric acid leads to bone loss” thing too, actually…but I spent some time poking around yesterday, and it looks like you’re right – the phosphoric acid itself doesn’t seem to be the issue. I should mention that I was still half-asleep from my long trip and didn’t save any of my references, but I do recall seeing the suggestions that caffeine might be an issue, maybe, or the sometimes-seen correlation between high-cola-consumption people and the possibility of low calcium might just be due to what one reference referred to as “milk displacement” (i.e. drinking more cola = consuming less calcium-rich dairy) or just the free phosphate causing calcium in the diet to precipitate out as calcium phosphate, inhibiting absorption.

    It seems to be easy to find anti-soda crusaders and well-meaning “nutrition” fans saying there is phosphoric acid in cola drinks, but at the same time it seems to be remarkably difficult to find any actual numbers showing how much phosphate is actually in them.

    Of course, my interest here has virtually nothing to do with human nutrition…

  3. The quantity varies, but you can find out yourself. See


    for instructions.

    It looks like we’re doing near inverse moves; I’m about to relocate my family from the southwest to the Pacific northwest, though I’m probably going to cut through Utah or Nevada rather than taking the front range route.

    — MarkusQ

  4. If it’s a part of the Pacific Northwest that actually has water and trees, I’m jealous (I definitely would prefer cool and wet to hot and wet).

    Well, I COULD find out about the phosphate myself, if I had a pH meter (yet another item on my list of Things I “Need”, along with a microscope). There actually DOES seem to be much less that one might be lead to believe from the screaming of the anti-cola people waving a glass of Coke® with a tooth dissolved in it. Still, thanks for the link, I’ve saved a copy for future reference.

    One of these days maybe I’ll be rich enough to buy my own HPLC unit.

    I may be better off going back to working on using powdered milk as a phosphorus source instead, though, especially if I can come up with a reasonably friendly way to hydrolyze it.

  5. I may be better off going back to working on using powdered milk as a phosphorus source instead, though, especially if I can come up with a reasonably friendly way to hydrolyze it.

    Have you considered bone meal (about 1/3 P2O5 by weight I think)? It should dissolve in something slightly acidic, so mixing it with a little citric acid should give you a good source of phosphorous without getting lactose and friends in the mix.

    (I don’t know much at all about what you’re doing, and only slightly more about what I’m suggesting, but I do know that even a tiny bit of butyric acid will make the results unpalatable, and I have an unsubstantiated suspicion that the risk of butyric acid production goes up when you start messing with lactose).

    — MarkusQ

    P.S. Yeah, we’re headed for the wet part, a ways west of Portland. Ten days from now I’ll be somewhere in Nevada in a car with two kids, two cats, and as much perspective as I can muster.

  6. Well…I do have an experiment that I absolutely must try eventually that relates to bone-meal, but not until I get settled in somewhere and have a proper setup where I can do a real experiment to see if it really does what I think it will do. (Hint: I actually suspect this stuff is better than it sounds, though that wouldn’t be hard to accomplish since it sounds pretty disgusting at first glance…)

    Bone being made up primarily of, as I recall, hydroxyapatite (a calcium phosphate mineral) cemented together with protein, it probably would actually make a good fermentation nutrient. I’m not sure how accessible bone meal is though – one of the goals of my current perverse experiment is to ferment something up using only readily-available “grocery-store” ingredients. Kind of like a comparatively upscale version of Pruno. Just for practice, of course.

    I’m not certain, but I think the major place one might get butryic acid due to the presence of milk would be from milkfat rather than lactose. I know some beers use lactose as an ingredient because Saccharomyces cervisiae won’t ferment it, so the lactose stays in the final product to provide some sweetness and body. I think if I stick with nonfat dried milk powder I should be okay. My main concern with it is really just how much it needs to be broken down prior to feeding it to the yeast – I don’t think Saccharomyces yeasts secrete proteases, so I don’t think by themselves that they’d be able to make any use of milk proteins, phosphorylated or not, without hydrolyzing it first.

    West of Portland? Okay, I am jealous. But at least I’ll be able to pump my own gas.

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