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food

Play to your strengths!

A friend tries her own hand at chopping open coconuts on Hainan Island.

I have a confession to make here. I suck at organic chemistry. Chemistry in general (general chemistry, organic chemistry, biochemistry) was by far my weakest subject in college (Cs the whole way). I even managed to fail organic chemistry lab one semester which brought be down below a full course load that semester and I had to organize an appeal to avoid being involuntarily suspended the following semester. It’s always fun to tell this story to new undergrads and or grad students and watch their eyes get wider and wider as the tail goes on.

The reason I tell them that story — besides to try to help put things into perspective when a kid is worried about getting their first B and that their own imagined future is crumbing before their eyes — is to make the point that it’s okay to be really really good at some things, and suck terribly at others. That’s why we come together as a society. If I’m really good at climbing trees to harvest coconuts, but suck at spearing fish, and you have the opposite skill set, one solution would be for me to spend all my time practicing fish spearing, and you to spend all your time practicing tree climbing. Or I could trade you some of my coconuts for some of your fish, and we’d both have a lot more to eat when we sit down to a delicious feast on the beach as the waves roll in.

I have no idea what these even are, let along how to make them, but I remember them being really delicious (Beijing 2014).

There is also such as thing as over-specialization. If I’m so focused on harvesting a particular type of coconut that I develop my whole own coconut focused vocabulary, to the point I cannot even communicate with people who spear fish, or farm taro, I’m going to have a bad time of it out in our hypothetical island world.

Thus ends this fable/analogy/whatever it is.

….also I’ve sucked at spelling since I first learned to write.

Why popcorn pops

Popped corn Photo: D3 San Francisco, flickr (click to see photo in original context

Popping corn, or anything else, all comes down to pressure. Pop-corn has a particularly impermeable pericarp (the corn kernel’s shell), so as it is heated, the water inside the kernel vaporizes into steam and the starch turns into something close to a liquid. Eventually the heat creates enough pressure to split the pericarp and the starch of the corn kernel bursts out, resolidifying into the distinctive shape of popcorn. If there is even the smallest hole in the pericarp, the steam can escape from the kernel as it’s generated so the pressure never builds up enough to explode the pericarp — the reason some kernels will fail to pop in every batch. The explosive build up of steam is also the reason tea kettles need to be able to release steam while they’re used to boil water. The alternative would be exploding tea kettles which are a lot more dangerous (and a lot less tasty) than exploding corn kernels.

Un-popped popcorn photo: MissTessmacher, flickr (click to see photo in its original context)

It was this reason (along with my discovery of the website on April 1st) that I was so suspicious of the idea of popped sorghum a few days ago. Thanks to Party Cactus and Jeremy, I now know that sorghum does indeed pop like corn (there’s even a variety called “Tarahumara Popping”) and, in fact, thanks to the link Jeremy provided, I’ve discovered that most grains and even some other things (including cowpeas!) can be popped using the proper equipment. (more…)

Corn Smut

Corn Smut photo: oceandesetoiles, flickr (click to see photo in its original context)

And no that doesn’t mean corn pornography*. Corn smut, or Ustilago maydis, is a fungus that infects corn plants. It’s an old acquantance from my days working in the field. We always used to tell the new hires that corn smut was a rare delicacy in some countries (as we’d been told ourselves), but this was in the days before iPhones so until recently I never actually checked on this bit of received wisdom.

Turns out this particular bit of knowledge was true:

The immature galls, gathered two to three weeks after an ear of corn is infected, still retain moisture and, when cooked, have a flavor described as mushroom-like, sweet, savory, woody, and earthy.

More corn smut. Photo: moskatexugo, flickr (click to see photo in its original context)

I haven’t been able to figure out what the trade off in nutrition is between the ear of corn that is produced by a normal plant and the fungal galls that can be harvested from a plant infected with corn smut. I’d imagine corn smut provides more (and more complete) protein than an ear of corn (assuming corn smut is nutritionally similar to mushrooms.) But what’s the comparison in number of calories? The fungus is certainly sold at a higher price pound for pound.

My renewed interest in corn smut comes courtesy of a new paper** that came out in PLoS Biology describing how the fungus steals energy from infected corn plants without triggering the corn’s usual anti-fungal defenses. It’s an interesting read, you can check out the paper itself since PLoS Biology is open access, or Diane Kelley’s summary at “Science Made Cool.”

I’d seen a number of talks recently about another fungal parasite, powdery mildew in Arabidopsis, but somehow it’s much easier to focus on this stuff now that I can connect it back to corn. Even mammalian systems can be interesting*** once the make that connection.

*Please PLEASE don’t let that phrase start showing up in the search terms people use to find my site!

**Wahl R, Wippel K, Goos S, Kämper J, Sauer N (2010) A Novel High-Affinity Sucrose Transporter Is Required for Virulence of the Plant Pathogen Ustilago maydis. PLoS Biol 8(2): e1000303. doi:10.1371/journal.pbio.1000303

***The talk I’m practicing for Monday actually uses an example of a pheromone receptor in new world monkeys that was lost 23 million years ago in old world monkeys (including us humans).

The Color of Corn and Cultural Values

MAT_kinase has sparked an interesting discussion about the associations people have with corn of different colors. I’d previously heard that yellow corn (where pre-vitamin A carotenoids are produced in the kernels) isn’t popular in Africa, with the reason usually being given as its association with American food aid.* If yellow corn comes predominantely from food aid, it eventually becomes associated with being poor and/or starving, so that when people have a choice they eat other varieties of corn. I can’t find where I read it, but I vividly remember reading an interview with a woman who talked about the shame of eating yellow food-aid corn, knowing that it had originally been intended to feed livestock in the US, not people.

MAT points out another more pragmatic reason yellow corn may not be favored in Africa that I hadn’t heard of before. Apparently the extra carotenoids make yellow corn more susceptiable to spoilage than white corn varieties, a very pertenent issue in areas without access to the kinds of storage facilities we take for granted in American agriculture.

Jeremy at the Agricultural Biodiversity Weblog picked up the torch, highlighting a number of their own previous posts relevant to the discussion, including one by fellow blogger Luigi that relates the reaction of his own wife, originally from Kenya, on ordering polenta** at a restuarant and receiving a yellow dish.

Fortunately breeds of corn that contain even more beta carotene (the carotenoid most easily converted into vitamin A by our bodies) aren’t even yellow all the time. Although I wasn’t able to find a freely available picture, sometimes they’re ORANGE.*** While it turns out the correlation between color and beta carotene content isn’t perfect****, there’s still reason to hope varieties bred for the highest pre-vitamin A content will end up a striking orange color. For a visual examples of how orange corn can get, check out check out Dr. Rocheford’s lab website.

Will the distinction between orange and yellow***** be enough to get over the Africa’s lack of enthusiasm for yellow corn? Will the benefits of a diet with more vitamin A be enough to outweight the issues with yellow corn going “off” if stored improperly? I certainly hope the answers to both these questions are yes, but we won’t know for sure until we try. And there are some hopeful signs. For example this segment in a story from NPR: (more…)

Not Genetically Engineered: The EverMild Onion

Sprouting onions. Photo: J. C. Rojas, flickr (click to see photo in its original context)

This isn’t a lot that is biologically exciting about the EverMild onion from what I can tell. Hopefully there will be more details on Monday when these onions are officially announced on Monday, but the short version seems to be that plant breeders at Seminis have developed a variety of sweet onion that can be grown in the pacific northwest over the winter, supplying sweet onions grown within the US at a time when they normally must be shipped in from the tropics or southern hemisphere.

So plant breeding has produced a new hardier variety of sweet onion* and is taking part in the new trend towards “branded” breeds of produce (like the Jazzman rice I talked about earlier this year). This would normally hardly be news (Seminis sells over 3500 kinds of seeds and they’re adding one more), and if it was at all, would be a story of reducing the demand for imported food with new varieties adapted to the US (again there are parallels to the Jazzman rice story). But I expect we will be hearing a fair bit about the EverMild onion at some point, because Seminis was bought by Monsanto several years ago, and I’ve alreadying read comments from people convinced it is a “secret GMO.” Nevermind that sweet onions (onions breeds that are lower in sulpher) have been around for a century. (more…)

“New” Cruciferous Vegetables

A stalk of brussels sprouts photo credit: cbmd, flickr (click for photo in original context)

Last week Greg over at Pie-ence was talking about the amazing variety of vegetable crops breed out of a handful of species within the genus Brassica, specifically Brassica rapa and Brassica oleracea.* I’m referring to these as cruciferous vegetables, which is actually a wider category including all the vegetables within the mustard family of plants (scientifically this is called the Brassicaceae). But one of the cool things about having so many kinds of vegetables within the same couple of species is that, because they’re the same species, they can still be interbreed with each other to create “new”** vegetables. (more…)

School Lunches

In yet another article on the evils of corn syrup, I came across a weird quote:

Because SFUSD has focused on reducing fat and empty calories in cafeteria items, the meals are now very close to the USDA minimums, and are based on a meal which includes either 1-percent white milk or skim chocolate milk. “Replacing skim chocolate milk with skim white milk would cause the calorie count of the meal to drop below the USDA-mandated minimum,” says Woldow [A member of the San Francisco School District Student Nutrition Committee]

I feel weird thinking about this. Cutting sugar (regardless of whether it originates in sugarcase, or corn, or sweet sorghum, or the sugar beet) from school lunches is a laudable goal. But free and reduced price school lunches are also the closest thing some kids will have to a real meal all day. So San Francisco School District, in the push to make school lunches more healthy, if nothing else could you please increase the portions for healthy things as you cut out the foods you don’t approve of?

Cutting calories from a program that has a real impact on childhood hunger and malnutrition in our country isn’t something you should be proud of.

And just to be clear all that happened in the article linked above was to substitute sugar (produced from sugar beets, or sugar cane) for corn syrup on a calorie for calorie basis.

Pumpernickel and Rye and Vavilovian Mimicry

Delicious pumpernickel bagel.

Its tasty but what is it? First, a disclaimer. I’m going to be discussing traditional pumpernickel bread. The kind pictured to the right is almost certainly modern pumpernickel which gets its color from dark substances like molasses or cocoa powder, and often is made with wheat flower rather than the traditional rye. But that’s a boring story. This one is more exciting!

(more…)

Not Genetically Engineered: Square Watermelons

Square watermelon. Photo: laughlin, flickr (click photo to see in original context)

This is an addendum to my previous post: Not Genetically Engineered: Watermelons

At the time I thought the only awesome thing about watermelons that people calling genetic engineering was seedlessness. It turns out there are also square watermelons. Are they genetically engineered? I guess my title does kind of give away the answer.

Square watermelons aren’t the product of genetic engineering, or radiation mutagenesis, nor even conventional breeding. (more…)

Support Sugar Beet Farmers

Earlier today I was sent out, through rain and fallen snow, to visit the local grocery store for various last minute cookie ingredients, including confectioner’s sugar. The only brand I could find had this prominent label:

Powdered sugar at the local grocery store

First of all I’ve never understood why people care wether a given cup of sugar come from sugar cane or sugar beets. Regardless of source, white sugar is at least 99.9 percent pure* sucrose. Sucrose is a single molecule with an exact structure that is the same regardless of source. (Like salt crystals, or de-ionized water it’s a pure substance, only one step up from elements like carbon and oxygen).

Sucrose molecule

A model of the sucrose molecule. All sucrose, regardless of source, will have this same structure. If it doesn't, it's not sucrose. Image from wikimedia and distributed under the creative commons 3.0 share alike license.

That said, I’ve never before seen a label on a bag of sugar that proudly announced what it is NOT (beet sugar). I don’t know if this is a reaction to the current publicity about herbicide resistant sugar beets, or the old feelings about the, non-existent, differences between sugars refined from different plant sources taken to their logical extreme, but either way, in this christmas of all christmases, is not the time to be kicking beet farmers when they are down. (more…)