Standard Pages (they don't change often)

Friday, August 23, 2013

Munching on tree trunks

Malaysian sago starch cookies.
In a prior post, I described the relationship between simple sugars, and more complex carbohydrates, like starches and glycogen. To summarize, starches are basically by linking together the smaller sugar molecules. The different types of starches (mostly a mix of amylose and amylopectin) differ primarily on how the sugar molecules are arranged. Glycogen is pretty much the same idea, except it's what animals make.

However, simple sugars can also be hooked together into a form that can't easily be broken down. When organized in such a fashion, these complex carbohydrates fulfill a structural function: cellulose. Due to it's strong and indigestible nature, cellulose is the primary component of wood. So, in short, the basic molecule of glucose (aka - corn syrup) can be hooked together to make either paper or bread.

The main reason to make starches, from the point of view of the plant, is for energy storage. After all, starches need to first be degraded into simple sugars before they are further digested for energy. That's why our most common sources of starch tend to come from grains (wheat, rice, corn). The starch there is primarily energy stored for the seedling to use when it germinates. Conversely, we can't digest cellulose, so the plant parts that aren't seeds are rich in fiber (indigestible cellulose that still serves an important "regular" function), and aren't starchy. But there's always an exception to the rule.

The sago palm (Metroxylon sagu) is harvested primarily for the starch content stored in the pith of its trunk. Sago starch remains an important dietary carbohydrate in Southeast Asia and Papua New Guinea, and may even predate rice as the dietary carbohydrate in China. Harvesting sago is a laborious process where the trunk has to be split, the inner pith is shredded, soaked in water, beaten to release the starch granules, and then dried. Sago starch has some optimal gelatinization properties between classic grain based starches and potato starch, and is remarkably free of protein - perhaps an important ingredient for those seeking gluten-free starches. 

Tuesday, August 13, 2013

Having a beef with the beef

Were you expecting a stock picture of a burger? This is still scrap meat dish. 
I listen to the podcast The Skeptic's Guide to the Universe, a well produced talk show promoting science and critical thinking, featuring a panel of "professional skeptics". In this week's episode, they actually touched on a story that's been making the rounds of social media and news sites: the lab grown hamburger. Or, as the producers at Maastricht University call it, cultured beef - funded by a grant from Google's Sergey Brin. The website is pretty slick, by the way, including some nifty animation.

This was no small feat - well, monetarily. The small patties cost over a quarter of a million dollars to produce - but to what end?

I am disappointed that the Skeptics didn't even question the premise of tissue cultured beef. They rained accolades on this as a major scientific advance, buying into the talking points from the Maastricht PR group, speculating about a future of harvesting meat from dishes, free from the cruelty of having to slaughter and butcher animals, and protecting the environment since cows need large expanses of land. Moreover, they bought into the misdirection, spending time on the disgust issues of eating laboratory produced cells and the flavor, rather than thinking about how this meat got to be where it is.

First problem: the Skeptics actually used the term "peak meat" - that there's an impending shortage of meat due to increasing demand, echoing the talking point that cultured beef technology solves a food security problem. Meat is a dispensable part of the human diet, can come from multiple sources, and beef itself is a luxury meat. Most of the world does not consume beef regularly because of cost. It has a lower cultural impact that you would expect on a global scale - unless you're viewing it from a privileged First Worlder point of view. Moreover, hamburger itself is simply creative use of scraps from the premium pieces of bovine used in beef production. If one were to take the trouble to build scaffolds, with single cell resolution to produce meat, why make an amorphous patty? Why not build a steak unlike any made before? It's like using a 3D printer to make a haystack.

So, what advances in tissue culture production did they introduce? Technologically, they employed few novelties that advance what we already know about stem cell differentiation and tissue culture. Just maintaining the sterile conditions needed to produce the cells can be quite energy intensive, certainly impacting the environment more than a cow or two. And what did they feed the cells to grow them? There's the ugly small print: fetal bovine serum (FBS). To grow animal cells outside of an animal, we have to simulate the environment of being inside the animal. That means a complex mix of growth factors and nutrients - this is provided by the FBS, harvested from aborted fetuses of cows. The efficiency is far from ideal as well - it takes a lot of fetuses worth of serum to grow a single patty of "cultured beef". In a weird sense, we are killing cattle to feed the "cruelty free" cultured beef. Media coverage is quick to handwave this requirement away as some small technical glitch that will be solved eventually, replacing FBS with a sustainable, non animal destroying substitute.  This does not exist, and the quest to make a synthetic replacement for FBS has been going on for decades - and we are nowhere near an acceptable solution. So, no scientific advances made in cell culture production techniques either.

The way I see it, it's a giant publicity stunt. All the focus on taste is a distraction from the very ornate art project. It's no real triumph of science, but it has sucked up enormous amounts of scientific talent and attention. I am not sure if this qualifies as pseudoscience, but the trappings were sufficient to get it past even folks as jaded as the SGU. Face it, for the foreseeable future, the most cost effective way of making beef is with a cow. But we can make it very merciful meat.

Do we really want culturable meat? Why not start with animals that are already easily cultured with minimal complex media requirements? For example, the starfish or the flatworm Planaria easily regenerate themselves when damaged - because they can revert to stem cell states easily and redifferentiate into any tissues required. Can we genetically engineer them to taste and look like beef? Or pork? Or chicken? Then again, I don't see the animal rights activists fighting to protect the lives of planarian worms from cruelty.

Update: Maureen Ogle isn't too impressed either. Specially considering the history of trying to culture meat.

Wednesday, August 7, 2013

A quick lesson in evolution

Fennel gone wild.
Two topics that I track for the purposes of science-based cuisine are the issue of genetically modified crops (notably, the use of glyphosphate resistance genes) and the use of antibiotics in farm animals. In both cases, farmers use a reagent chemical to eliminate undesirable organisms (weeds or infectious bacteria) from the population of desired plants or animals. Whenever these technologies are described, the specter of resistance is also aptly invoked, which limits the useful lifetimes of these methods. The choice of words that the popular media uses, however, can be infuriatingly misleading in its oversimplification.

The most common mistake is to say that "bacteria become resistant". So, here is a quick lesson in evolutionary biology. The vernacular language tends to treat bacteria as an individual, but really, it's a population going through changes. And the basic thing to remember is: the resistance mechanism is already in the population. The treatment with antibiotics did not create resistant organisms - it simply selected for them to increase in population frequency.

But perhaps more exasperating is the frequent populist writing about "creating superweeds". Coined by antiGMO activists, superweed is a poorly defined term meant to bring up the specter of unkillable weeds. By definition, a weed is simply an undesired plant growing in an agricultural set up competing against a desired crop. The technique of engineering crops to be herbicide resistant opens up the method for using herbicides to kill off weeds - but, eventually, the resistance mechanisms will increase in frequency among surviving plants going on to the next generation. It's simply evolution in action. There's nothing super about it.

Tuesday, August 6, 2013

Fishier than the salmon

In the Houston Press blog, recently appointed food critic Kaitlin Steinberg posts an article called "Attack of the Frankenfish", which is, of course, about the potential (and long delayed) approval of the Aquabounty transgenic salmon to the US markets. The writing uses the leading epithet "frankenfish" twice, painting immediately in the reader's mind that these are some kind of science fiction monster, despite the conciliatory wording admitting that the fish are only different in their growth rate - they grow twice as fast as their unmodified kin.

After that, Ms. Steinberg starts citing the Center for Food Safety. Despite the seemingly authoritative name, the CFS is a political action group dedicated to the elimination of genetically engineered foods, regardless of facts. They have resorted to outright fabrication and falsehood in marketing.

The Center for Food Safety, under its façade of nonprofit watchdogging, has all the marks of a black-marketing campaign, run on behalf of organic and “natural” foods. Its advisory board is packed with organic-foods activists.
Sadly, Ms. Steinberg was suckered in by this shady group. Although she writes that there are "Many organizations like the Center for Food Safety " which have petitions against the Aquabounty salmon, she fails to cite or link definitively to any one of them. But if they are like the CFS, they shouldn't be trusted anyway.

The environmental impact should be no different than for any aquacultured fish (I'd be more concerned with tilapia). As for the issue that the salmon could contain higher amounts of antibiotics - I refer you to my earlier postings about antibiotics in agriculture - a complex issue that merits much more thought than a simple condemnation. Mentioning it in ominous handwaving is manipulating the emotional susceptibility of the reader - this is not backed by any actual science. Then again, that's what the CFS really does - it subverts the air of scientific authority to spread unfounded fear.

At the end of her posting, Ms. Steinberg falls into the usual rhythm of anti GMO fearmongering, cautioning people to look for "wild" salmon, to avoid this product - even though it hasn't even entered the market yet. Poor Kroger is the unfortunate collateral damage of this inadvertent smear campaign, unfortunately named simply for not committing to a business move that they cannot control.

I suggest that Ms. Steinberg rethink her role in being the tool of a manipulative unscrupulous media entity.