Just another flavor separation technique

posted by Mindy Lvoff

As I was discussing how to describe (and understand) “countercurrent chromatography” (CCC) with Dave and our friend, Philip Preston of Polyscience (who stopped by FCI today to hang out for a while), Philip summarized the process as “just another flavor separation technique…”  Easy to say when you’re a genius, but I needed a little more detail.  Dave continued that where our centrifuge separates based on density and our rotovap separates based on volatility, CCC separates based on polarity.  The good people of Cherry Instruments have been working on a way to use liquid-liquid CCC in relation to food and flavors, hoping that perhaps this gadget will eventually make the leap into the kitchen.  At some point, Dave will chime in and fully explain what the process is, but in the meantime, here is my best attempt at a layman’s explanation (and thus the depth of my understanding): our Cherry Instruments friends are using a centrifuge to hold oil (non-polar) in place as they pump a polar liquid such as ethanol or water through the oil like a filter – thus the “liquid-liquid” designation.  Different flavor compounds with different polarities will pass through the oil filter at different rates, with the most-polar coming through first with the polar liquid.  Therefore, where our current methods of separation (rotovap & centrifuge) allow only subtle flavor separation, whereas the liquid-liquid CCC process, Dave explained, “allows us to separate and layout different flavors like piano keys.”

Coffee, Spearmint & Menthol oil, & Oregano oil separated into different flavor notes using Countercurrent Chromatography
Coffee, Spearmint & Menthol oil, & Oregano oil separated into different flavor notes using Countercurrent Chromatography

We were given 3 different compounds that were broken out into their many flavor components: Coffee, Spearmint & Menthol oil, & Oregano oil.  For these, ethanol was used as the polar liquid.  The 3 coffee vials that we tasted broke out smokey notes in one, bitter notes in another, and a slight sweet note in the third.  The mint oil was a much more forceful demonstration with one vial basically tasting like pure menthol.  If you’ve never had straight menthol, it’s a little like shoving a Costco-sized package of menthol throat lozenges in your mouth at once.  Luckily, we had already tasted straight menthol before, so we were just upset vs. shocked by the experience.  The oregano oil was the worst, but luckily we could barely feel our tongues, let alone taste much, after our bout with the menthol.  Bitter oregano notes taste like oregano that’s been boiled until dead and then burned at the bottom of a sauce pot.  By the time we were done, all I could taste and smell were smoke, menthol, and bitter oregano.  It reminded me a little of college.

An innocent looking vial of menthol-flavored pain
An innocent looking vial of menthol-flavored pain

The flavor note tasting, while traumatic, did help illustrate the CCC possibilities: you can either isolate a flavor note that you want to use specifically or conversely, remove one flavor element such as bitterness that detracts from whatever you are breaking down.  In our case, we thought of our Habanero Vodka technique and suggested trying to remove the capsaicin from Habaneros, or perhaps even isolating out some of the floral notes.  We also thought of removing the tannin flavors from teas.

What else do you think the good people of Cherry Instruments should try and separate???  Send us your comments and we will pass them along and keep you updated on their progress!

10 thoughts on “Just another flavor separation technique

  1. You could presumably make the “perfect” whiskey (different for everyone). This only works if you can isolate the compounds in the non-oil portion. Could you put cheap whiskey in one end, flavorless oil in the other, then use distillation to recover the broken-out “piano keys” from the oil?

  2. vanilla, toasted almond (or anything with maillard flavors, really), peach, blue cheese, and durian all come to mind.

  3. In response to Jeremiah. If you were to pump whiskey through flavorless oil the whiskey flavors would “stick” to the oil to varying degrees. As the whiskey comes through the oil the whiskey flavors will come out in “fractions.” (assuming things don’t go horribly wrong for unforeseen reasons) In other words, the flavor compounds would be separated in a spectrum based on how “sticky” they are to the oil. (ie the stickier they are the longer it will take for them to come out) To do it right, this experiment would require extra whiskey and shot glasses. Salute!

    And Jeffje, I think you are onto something with your thoughts on the maillard flavors. It turns out CCC can separate them from other flavors quite well because they are very polar compared to most other flavors.

  4. On another (floral) note, this looks like a technology with culinary potential:
    http://www.popsci.com/scitech/article/2009-08/news-flash-land-oktoberfest-longer-lasting-brews

    A polymer is custom-designed to bond with one specific molecule (in this case riboflavin). Dip the polymer in beer and it pulls out all the free riboflavin (which otherwise can react to light and produce off-flavors).

    Presumably the same technique could create custom polymers to extract any molecule you like.

  5. heatless habanero is a no-brainer. the one thing that countercurrent chromatography is really best at is “chemical subtraction”, i.e. remove only specific compound(s) from highly complex mixtures. just pull out the capsaicinoids and you have heatless habanero.
    “assuming things don’t go horribly wrong for unforeseen reasons” is not anything I like to think about. just make it work and it will work.

  6. I’d term chromatography in the kitchen among the more hard core techniques 🙂 Removing off-flavours, such as oxidised fatty acids from rancid oil (might be put in the category of misuse, though).

  7. what about the citrus notes from different hops? or maybe like pinky came up with on “Pinky and the Brain,” make pencils that taste like bacon, or even bacon that tastes like pencil’s.

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