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Thursday, July 31, 2014

Will Vegan Cheese Work?


A recently funded Indiegogo campaign to make "Real Vegan Cheese" has been brought to my attention recently. It's quite an impressive project for "biohackers" - a promise to make "real" (we'll come back to that) cheese without involving cows. And the speculation about it is feeding the narrative for the reporters on the science beat.

But this really isn't a science question. It isn't teaching us something about the natural universe - it pokes at our cultural definitions of cheese, veganism, and food in general.

To start with, the campaign makes some scientifically dubious promises and allusions - for example, they prominently claim that the "real vegan cheese" will not contain GMO even though they'll be using genetically modified yeast because they are purifying the casein protein. This shouldn't matter to those who worry about GMO contamination (otherwise, there wouldn't be objections to sugar produced from GMO sugar beets). Or the claim that this method of cheese production will be more sustainable than the status quo - there's no data for this. After all, one should consider the inputs to fabricating all the components. And even more dubious is the promise of lowered allergenicity in the product by modifying the casein produced - hypothetically possible, the process is far more complex than they imply, and could affect the product itself.

The challenges are huge. The prerequisite that isn't discussed is they plan to make a "vegan milk", which is thought to be a simple mixture of protein, fat and sugar - but milk is far more complex than that. Milk is chock full of a structure known as micelles which are serve to hold on high concentrations of calcium for delivery to offspring. In fact, caseins (there are more than one kind) are thought to have evolved as a calcium retention mechanism, and building the milk micelle isn't a matter of mixing things together in a blender - and this type of macromolecular assembly is key to how curds form, and cheese to be made. And leaving out lactose means that the microbes that can be supported would be quite different from the conventional cheese production.

So, will it work? Can they make it?

Does this question matter at all?

They will make a product - but will it be cheese? What is cheese anyway? There is a legal definition of cheese, which is tied to a definition of milk (and there is a biological definition of that - and it's tied to animal production). By this alone, they probably cannot call whatever is made cheese (similar to how a product can be called an ice cream or a mellorine).

Moreover, the quest serves the point of veganism - which is itself not a scientifically defined practice. Evolutionarily speaking, yeast are pretty closely related to mammals relative to flowering plants, but to the vegan demarcation - they're vegetables. This is an arbitrary classification that serves a cultural whim, seeking a food product that is itself a luxury. In short, it's very much a first world problem. While not as much of a publicity stunt as the "cultured meat" project, this project is just as devoid of science all the while dressed up in the robes of scientific practice. But it has carried the imagination of the public enough to get funded. Good luck to them, and to everyone who has invested in it.

Thursday, June 26, 2014

Not all white bread are equal

I respect Scientific American as an science communication institution - over they decades, they've evolved from the classic magazine to the myriad online avenues, from blogs to Twitter and podcasts. But I fear that in the zest to embrace the age of the soundbite, some of the care may be slipping. A recent 60-second podcast by Karen Hopkin reports on the potential "health benefits" of white bread. Most of these snappy one-offs are really a populist summarization of the results of a recent academic publication - in general, I approve of this, as the culture of scientific publication still favors dense writing that requires specialization just to read. However, simplification should not happen at the expense of accuracy.

Yes, this is white bread.
The report is about the unexpected association of Lactobacillus (a "healthy" marker in the micro biome) with the consumption of white bread, so it prominently begins with the mention of Wonder Bread. This, of course, is a byproduct of the America-centric nature of the target audience, to whom white bread is synonymous with Wonder Bread. But the study was conducted in Spain, and white bread in Europe is markedly different from the ubiquitous ""glutenous slab".

So, how was the study conducted? The authors selected 27 female and 11 male volunteers, aged 56-67 years old, and asked them about what they recalled eating from a selection of 160 items within the past year. After the interview, they collected one stool sample, and analyzed it for DNA. It isn't just any 38 healthy individuals - the data is based on the recollection of middle-aged to older volunteers (heavily skewed to women) from their diets a full year prior, and the stool sample came from one time point.

Though not explicitly stated, the misled hordes of the internet now parrot the line about how white bread (somehow equivocating to Wonder Bread) can be a healthy item. But it is a correlation, and at best a promising line of research. But I am dismayed that science journalism tends to lean towards this need to sell a particular story frame, toying with the very edges of veracity, often misleading lay readers to the wrong conclusion, by selectively glossing over details, or (as in this case) introducing "facts" that weren't in the original paper to begin with. I cannot call this outright lying, but its effects can be more insidious. In the name of "spicing up" a story, a writer can pretty invert the conclusions of a study or report, manipulating the expectations and emotions of the reader. This is a powerful skill, and should be used judiciously.

Tuesday, June 24, 2014

Environmental Impact of "Cultured Meat"

Frog Legs, A Ly, Houston, TX. I'll bet we'll have better luck mass producing tissue cultured frog meat. 
I have previously described my problems with the mainstream media fascination with the "cultured meat" project. But recently, I've been contacted by journalist asking what my opinion is about the published dramatically lower environmental impact from culturing meat as opposed to conventional animal husbandry.The paper cited was published in 2011 by the American Chemical Society's Environmental Science and Technology, authored by Tuomisto and Mattos, claiming a dramatic 45% lower energy use, 96% lower greenhouse gas emissions, and an amazing 96% lower water use. Indeed, this is the paper cited by culturedbeef.net among its FAQs as a key advantage for tissue cultured meat.

So, let's see what the paper reports. Since a cultured meat production industry doesn't really exist, the paper is basically a fairly complex thought experiment. It presumes the existence of such an industry, and compares it to current beef, sheep, pork and poultry production. This is a vaporware comparison - the authors could assign all sorts of properties to the hypothetical cultured meat production, and we cannot contest it. But if we assign time to when such a pipeline would exist, the evolution of conventional meat production would have also improved in efficiency. In the end, though, this paper does not such prove anything, nor does it actually lead to testable hypotheses. In a sense, it isn't really falsifiable, and makes for poor science.

But such a thought experiment begins with a number of assumptions - and did the authors make reasonable assumptions? Aside from the laughable comparison of value since a number of products come from whole animals other than mincemeat, while culture vats will only make meat, there's the near magical creation of new technology. From the abstract:

Cyanobacteria hydrolysate was assumed to be used as the nutrient and energy source for muscle cell growth.
This is already a problem. Under no circumstance have we proven that conventional animal meat tissue can be grown using cyanobacteria hydrolysate, that raw proteins can be pumped onto cultured muscle cells and they'll metabolize it. Either the authors are ignorant of basic biology of isolated animal cells, interchanging them with yeast cells, or have conveniently cherry picked past this fundamental point. Moreover, the authors write:

The production of growth factors and vitamins are not included in the study as the quantities needed are small (under 0.1% of the DM weight of the media), and therefore the environmental impacts are negligible.
This is a grossly incorrect assumption to make. Despite the lower per weight composition of these micronutrients and growth factors, they are essential and difficult to isolate and synthesize. We have no substitute at the moment for using fetal bovine serum at the moment specifically because this fact. The cells will not grow without these growth factors, one cannot gloss over the environmental impact of harvesting and isolating this material. It's like ignoring the environmental impact of diamonds because they are so small - when in fact mountains can be destroyed to get them.

So, let's do a little background research. This press release from Oxford University (Hanna Tuomisto, the lead author, was a PhD student there at the time) hides a small note at the end: the research was funded by New Harvest, a nonprofit dedicated to cultured meat production. On the border, I would think of this as a conflict of interest. After all, it's a vaporware review that has been used in the last 3 years to claim advantages with regards to environmental impact, but it stands on fantastical unproven promises.

Thursday, June 5, 2014

Fructose alarm?

I came across an article on the science blogging site Science 2.0 stating that soda and juice companies are lying about fructose levels (that's pretty much the headline). It is a parsed summary of an accepted manuscript for the journal Nutrition which analyzes the fructose content of popular packaged beverages made with and without high fructose corn syrup. The article is critical enough to note that the fructose to metabolic syndrome connection is at best tenuous (and a poor approximation of real diets), but the charge that manufacturers are intentionally misleading customers with regards to fructose is bothersome.

To make the charge that someone is lying (or in this case, whole cadres of manufacturers - which only eggs on conspiracy theorists) is a fairly serious interpretation of the case. Does the evidence support this? The authors of the paper purchased samples of the different drinks, and analyzed them with various methods to measure the sugar composition of each sample. A bit of introductory chemistry here: glucose and fructose are simple sugars - when combined, the form sucrose, what we all call table sugar. More importantly, glucose and fructose are isomers - basically, they use the same atoms, but are just arranged differently. In fact, one can convert glucose to fructose and vice versa through a process called isomerization.

Corn syrup is mostly glucose. High fructose corn syrup (HFCS) is made by isomerizing part of that glucose into fructose - in fact, what makes HFCS "high fructose" is usually just 55% fructose to 45% glucose, rather than the 50-50 mix in regular table sugar. There are different grades of HFCS, depending on the amount of fructose therein.

So, the authors claimed that a significant portion of the sodas supposedly made with sucrose still contained free fructose, and that for a good portion of the sodas made with HFCS, the fructose was proportionally higher than the 55% that should be in the food grade HFCS. Does the data bear this out? Fortunately, the paper included the raw data, and I replotted it (after discovering a minor summation mistake in it).

Red circles denote drinks made with sucrose, blue are drinks made with HFCS. 
First of all, they only sample 4 drinks with sucrose. The drink types vary widely in flavor and formulation, but most cluster around the 55% mark - even those made with sucrose. But we also know that sucrose degrades into the simple sugars simply by heating it into syrup - so the fructose content could easily be a byproduct of the processing. The paper actually takes this possibility into consideration - but quickly discards it as unlikely, without reference and any further explanation. Reviewers should have picked up on this contention.

This does lend credence to the idea that by the time it gets to market, HFCS and sucrose are functionally identical. There is the one outlier - the Sierra Mist Natural which seems to retain much undegraded sucrose. It could be something peculiar with that manufacturer: seems to me that there is reasonable doubt here contend that the manufacturers that claim to use sucrose are actually secretly substituting HFCS just based on this evidence alone.

The other is that the drinks are higher than 55% proportion of fructose - a reasonable number of them are also below this magic 55% mark. This is within statistical deviation, and could be explained by simple manufacturing variation or even storage isomerization. But even if they are consistently higher than 55% - I don't think the drinks are labeled to disclose that they are at most 55% fructose. Only that they are made with HFCS - which they do disclose. After all, even at 75% fructose - it would still be called HFCS.

How does this support the contention that there is "lying" going on? This is a potentially libelous situation, as none of this supports evidence of the intent to mislead, or failure to disclose. At best, there is a hint that a manufacturer may be taking shortcuts, but it won't be from this kind of analysis.

Words such as "lying" carry weight. I should hope that science reporting will be more analytical, rather than parroting the frame that the authors of the study wish inject, to bring some kind of ominous implication of conspiracy based on flimsy evidence.

Thursday, May 29, 2014

Bonding with the Bedrock

"What did you think of the tres leches flavor?"

My companion and I looked at each other as we discarded the sampling spoons, thanked the gelato vendor, and walked away from the colorful freezer case. We had intended to get some gelato from an inviting display, and after tasting five different flavors, came to the same conclusion: the actual gelato cream base had too much overrun. The flavors themselves didn't matter, the resulting product was an insipid castle built on quicksand.

Sadly, in many situations, food providers try to use accouterments overshadow the fundamentals, and this seems to be the case in popular discussion. For example, with pizza, the discussion is often about what the topping is, be it fontina cheese or "Thai" chicken or 25 different options. The crust itself is lost in the equation, mentioned by pizza aficionados but a discarded nuisance on paper plates for most of the public. Sushi judgements are almost always discussions about the quality of the fish used, but in its essence, sushi rice preparation is the foundation to the custom and cuisine.

And then, there's bread. In most cases, bread seems to be treated as a humble carrier for something else - the forgettable supporting character in an overstuffed sandwich, or sometimes to be discarded as the purveyor of "carbs". But good bread - there's nothing quite like it.

At its most basic, bread is a showcase of technique. From very few ingredients, one can produce anything from a baguette to focaccia, but we don't have many bakeries of distinction in Houston, bakers that take pride in the art of bread. So, with great interest, I've been sampling the wares at the newly opened Common Bond bakery.


Without a doubt, Common Bond portrays itself as a premium purveyor, with pricing to match. The packaging alone is reminiscent of a department store rather than a country baker. And most of the customers seem to be  agog with the pastries (special mention to the kugelhopf), and prepared dishes, but my focus has been on the bread products. I did sample an eclair, and found it rather disappointing, the choux texturally unpleasant.
Of the laminated breads, the croissant is a triumph of texture. Simply picking it up felt unreal, as nothing so large could be so light. The layer puff out, and is like eating baked air. At the same time, I found the flavor strangely bland (with a bitter undertone - not unpleasant). Maybe this was designed to be complimented with a jam, on its own, it was rather unremarkable. 
Given the opportunity, I'd recommend going for the Kougn Amman instead. Laminated in butter and sugar, the bread sits on a thin layer of caramelized sugar - the Common Bond staff wisely stack these upside down given the Houston humidity. I know of no other bakery in town making these treats, which make terrific desserts.
Among the regular loaves of bread, Common Bond keeps a fairly small repertoire of types: a baguette (and a couple of variants), a sourdough country loaf, an olive walnut loaf, and a pecan pear loaf. I see this as a kind of focus on the bread baking execution, and it shows. Though a little costly at around $7, the bread loaves are enormous and substantial. Moreover, I am impressed at how long they keep (don't refrigerate bread - it accelerates staling). In the case of the bread, I find the cost differential justifiable.

The country sourdough loaf is the most "general purpose" bread they carry.  It's a fairly mild tang, though I am curious as to the sourdough starter they use. Is it something that reflects the terroir of Houston? 
The olive walnut loaf took a little getting used to. The strong olive flavor meant that this is a bread for savory applications. Even butter didn't really go well with it, but a soft camembert complemented it well, particularly given the beautifully hearty mouthfeel to the crumb, and the robustness of the crust. 

On the other end of the spectrum, the pecan pear loaf is decidedly on the sweeter side of things, though not overly so. I did find it easier to pair this bread since the pear wasn't as assertive as the olives. Some meats go fairly well with this bread. 
The baguette is about $3 - which compares to the $1 or so the Vietnamese bakeries around town charge for a baguette. But these are very different breads. The Common Bond baguette hews more strongly to the European tradition, producing chewy, crusty loaves that hold up well to a tomato and some cheese. And like any baguette, they stale rapidly, becoming rock hard within two days. I wouldn't waste stale baguettes, but consume these quickly. 
I'm no stranger to baking, and I still think that having hot bread coming out of one's oven is likely to be the best experience - nonetheless, I am quite impressed with the Common Bond bread offerings. It'll come in handy as the Texas summer heats up.

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