The Sweet Science of Artichokes

Feb 17 2010

i wanted a picture of artichokes boxing, but this'll have to do. image from 

At least you’ll never be a vegetable—even artichokes have hearts. –Amelie

I suspect that one of the reasons artichokes show up in appetizers so often, especially in the sugar-loving U.S., is that they make everything you eat or drink for a little while afterwards, including water, taste slightly sweet. It’s not quite the simple straightforward sweetness of sucrose, which I’m not sure would be an especially desirable effect no matter how much you like sweet things. Instead, it’s more of a sweet-savory enhancement, perhaps even a little bit umami.I cropped the chart description for length, but will happily send it to anyone who's really interested

According to a 1972 article in Science, the first written account of artichokes’ capacity for taste perversion followed a dinner for biologists at the 1934 AAAS conference. The salad course consisted of globe artichokes, and someone must have taken a survey—of the the nearly 250 biologists in attendance, 60% reported that after eating the artichoke, water tasted different, a difference most of them described as “sweet” but a small number said was “bitter.”

The Science article reports on the results of an experiment that showed that artichoke extract modifies the taste of water by temporarily affecting the tongue rather than the food or drink (which makes it different than saccharine, which can make water taste sort of sweet and/or bitter as residue on the tongue is re-diluted). They also isolated two molecules found in artichokes—cholorgenic acid and cynarin, and found that both, independently, had a similar effects on the perceived sweetness of water as adding 2 tsp. sugar to 6 oz. water.

However, a less formal acknowledgment of the strange effects of the artichoke exists in the ancient folk wisdom that artichokes are “impossible” to pair with wine. An article in Wine News Magazine claims to “dispel” the “antiquated myth” of impossible pairings, but many of the suggestions purport to work by minimizing the presence or effect of the cynarin, either by boiling the artichoke in "ample water” or serving it with acids like lemon and/or mayonnaise. Leaving aside for the moment the question of whether either technique actually does anything to the cynarin and/or chlorogenic acid, I’m not sure that eliminating the chemical basis for the unique taste of the artichoke passes muster as a successful “pairing.” Essentially what they’ve done there is pair the wine with a less-artichokey version of the artichoke.

The Science article notes that the effects of cynarin and cholorogenic acid last longer than the sweet taste of sugar or saccharine, but are weaker and shorter-lived than that of miraculin, the protein in “miracle fruit.” Miraculin works by adhering to sweet-receptors on the tongue and acids in food, which makes the acids activate the sweet-receptors. I tried that with a bunch of friends shortly after The New York Times reported on it, and it really is trippy—lemons taste like candy, goat cheese tastes like cheesecake, and we all got stomachaches from eating so much acidic food in such a short period of time.

However, the protein miraculin seems to affect a much larger percentage of the population than the acids in artichoke. Just like at the AAAS dinner, a large number of the 1972 experiment’s participants didn’t experience a sweet taste after consuming artichoke extract. And again, a very small number actually said that the artichokes made water taste bitter. So it seems like cynarin/cholorgenic acid must have a different kind of mechanism, one that works for a majority of the population but exempts a substantial minority. Sadly, I can’t for the life of me figure out what it is. Does it inhibit bitter receptors? Attach temporarily to a certain kind of sweet receptor not everyone has? It seems to make white wines taste more sour, so perhaps it inhibits the tongue from registering the sugars in the wine? I don’t know, and I have searched. If you know, please share.

Anyhow, back to the question of what might alter or inhibit the cynarin and/or cholorogenic acid. In a post on "Transcription and Translation" also largely based on that 1972 Science article, biochemist Alex Palazzo claims that “pickled artichoke hearts don’t have this property.” I’m not entirely convinced, although this might be an issue of semantics. I won’t dispute that the sweetish aftertaste of canned or jarred artichokes seems muted in comparison with fresh artichokes, but I swear that even in that ubiquitous creamy, spinach-filled dip, or as a pizza topping, or in salads, or when added to paella, artichokes preserved in brine do contribute a subtly-sweet taste that affects the entire dish and any accompanying beverages. However, again based on my own subjective tastes and personal experience, marinated artichokes have little or no sweet aftertaste.

The difference seems to be that marinades, by definition, contain acid whereas brines typically do not—brines are just salty solutions. Now, pickling can imply either. Traditional pickling methods involve fermenting foods in brine, with no added acid. Their sourness is a product of the acids produced during fermentation. The more common form of pickling today begins with a solution that has added acids, usually vinegar. If Palazzo was referring only to the latter method—which would be artichokes labeled “marinated,” I agree with him. That also makes sense with the chefs’ suggestions to add acids in order to make artichokes play nice with wine; added acids must interfere with the cynarin and/or cholorogenic acid in the artichoke. But salt doesn’t seem to. Artichokes sold canned or jarred in brine (also technically “pickled”) still make food taste sweet.

Tomorrow, as this is apparently becoming artichoke week, I’ll post a super-easy recipe you can try to test the effects of artichokes in brine for yourself.

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