The future tastes bitter: climate change and the flavors ahead

This past December, my husband and I were invited to participate in an Iron Chef cook-off, where contestants were given an ingredient and had to create the most interesting, delicious and unusual dish possible. This was a challenge that we thought we’d mastered – we’ve previously won cooking competitions galore (first prize key lime pie, Mexican chocolate cake and cranberry wontons, to name a few). Victory was assured.

It started off promising enough. We had been given the challenge of chestnuts, and decided to do something really unusual, never attempted before – a persimmon chestnut upside-down cake. Persimmons, when ripe, are mild and sweet, and we were certain they would match the rich flavors of the chestnuts. What we didn’t realize was the inherent risk of cooking with chestnuts and persimmons, as both when unripe or not prepared correctly are laden with cotton-mouth-causing, bitter tannins, a secondary compound created by plants for defense against herbivores (bugs and people alike). Due to poor preparation on our part, rather than making a delectable heavenly treat, we made an upside-down cake from hell.

The lessons of secondary compounds as plant defense became clear to me that evening as we handed out slices of the bitter treat – not only had the plants been well-defended from human herbivores, the cake ended up well-defended too. We lost to a parsnip wine cooler and a teriyaki beef Christmas tree.

Alas, with climate change, Iron Chefs the world over will need to start rethinking their cooking strategies, because many defensive compounds that land plants use to protect themselves from herbivores (making a perfectly lovely leaf or fruit noxious to eat), will actually increase with more carbon dioxide in the air (1). This may be good for plants, because hey, more protection from horrible chomping insects, but not as good for those who are seeking a good meal.

What’s interesting is that plants in the water — sea grasses and the like — may not respond the same way as land plants. Rather than increasing their defensive compounds with increased carbon dioxide, they actually seem to reduce their concentrations with more carbon dioxide (2). This is probably not a great thing for those plants, but it’s certainly ideal for anything eating them (yum! Sea grass!).

Ok, so you are probably wondering what eats ocean plants, to which I say, what doesn’t eat ocean plants? Fish, turtles, hippies. If you are an underwater plant-lover, it could be a lovely future for you.

So of course the cynics out there are saying, “Aha! I knew that climate change will be good for something!” But much like that blind date you went on last week, it’s sort of a mixed bag – yeah you got a free dinner out of it, but did he have to fart through the whole second half of the movie?

Take green sea turtles. As I’ve mentioned before, the gender of the sea turtles is temperature dependent (3), i.e. higher temperatures during incubation equals more lady turtles hatching. With climate change there is a risk of it being ladies night all the time — Whoop! Whoop! But alas, imagine what it’s like to be one of those lady turtles – yeah you’ve got your sisters and sea grass and all, but few dudes which means less turtle love, which maybe not the greatest trade off ever? I mean, I don’t know too much about turtle lovin’, but they seem to keep doing it, so they must be into it.

So whether you are an iron chef or a grass lovin’ turtle, change may be on the horizon for consumers everywhere. In the meantime, I’ll keep working on my desserts – perhaps next time I’ll choose something a little more assuredly mild – forget chestnuts or persimmons, how does an eel grass brioche sound? Too rich?

Further Reading
(1) Global Change Effects on Plant Chemical Defenses against Insect Herbivores
(2) Ocean Acidification and the Loss of Phenolic Substances in Marine Plants
(3) Climate change and marine turtles

Minda Berbeco has a PhD in Biology from Tufts University and is the Policy & Programs Director at the National Center for Science Education. She wants to apologize for the turtle love videos posted above, because they were weird. But let you know that if you didn’t click on the links, you should go back and do so now. Because whoa, animals are weird.

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