America is much abubble concerning a mysterious string of pet deaths and illnesses.
Dogs and cats have been keeling over with kidney failure, apparently caused by pet food.
China comes into the picture because contaminated Chinese wheat gluten is the focus of US investigations.
The gluten’s exporter of record is one Xuzhou Anying Biologic Technology Development Company.
But by its own admission, Xuzhou doesn't produce wheat gluten for export. It buys from other factories and resells. Finding the producing factory might provide a clue as to how the wheat gluten became contaminated.
Anying has discretely removed wheat gluten from its product list, but its offering survived on one of the innumerable Chinese on-line bulletin boards meant to facilitate business-to-business commerce (the magnificently named "Ubiquitous Value Network"; last I checked the server was down, but I had previously printed out Xuzhou’s solicitation to sell).
The spec is distinctive, a low quality material with wet-based protein > 64%, dry base > 66%...you get the picture.
Anyway, the only place I could find offering that identical spec was an outfit in north-central Shandong, called the Binzhou Rongchang Biologic Technology Development Corp 滨州荣昌生物科技有限公司 .
Binzhou is in a wheat-producing area crisscrossed by tributaries of the Yellow River, with two large flour mills.
Unlike Xuzhou, Rongchang bills itself as a producer (and not just exporter) of wheat gluten (谷朊粉to the trade).
Not a 100% lock but certainly a good possibility that the wheat gluten came from Binzhou.
Having come up with a defendable hypothesis for the source of the wheat gluten, I'll engage in risky speculation.
Fortunately, I'm not alone. The pet food poisoning has been something of a puzzle for a lot of experts.
Labs have been picking over the wheat gluten but have been unable to identify an unambiguously toxic component.
A lab at Cornell originally declared on March 23 that it had detected aminopterin—identified as a rat poison--in the wheat gluten.
That sounded promising: wheat + rats + poison + sloppy housekeeping = contamination.
But it turns out that aminopterin is an anti-leukemia drug. Its identification as a rat poison in actual use is a canard, based on a reference from an American Cyanamid patent.
According to the ASPCA, the descriptions of distress they are hearing aren’t consistent with aminopterin.
Also, the FDA couldn’t find aminopterin in its wheat gluten samples.
What they did find was melamine—up to 6.6% contamination, with the crystals "clearly visible" . And there were reports that melamine crystals were found in the kidneys of some deceased pets.
Problem is, melamine isn’t considered to be particularly toxic.
So scientists are theorizing about how the nitrogen in melamine somehow got converted into some highly toxic derivative that smoked the victims’ kidneys.
Well, what interested me about the whole issue was my mis-spent youth, much of it spent in Chinese grain and chemical plants.
Wheat gluten and melamine really don’t go together.
For one thing, melamine is considerably more expensive than wheat gluten. No unscrupulous exporter is going to cut wheat gluten with melamine to increase his profits.
Second, wheat gluten is produced in wheat milling plants in China’s grain handling and processing network using an old and simple technique. Then the stuff is bagged and sold to food and feed processors.
Users rely on wheat gluten’s ability to absorb a great deal of water and become sticky to make their products—like pet food—all yummy-gummy instead of slurping out of the can in disgustingly distinct streams of fat, water, innards, cereals, and whatever else goes in there.
There’s an international demand for wheat gluten, it’s one of the more profitable outputs available to the traditionally impoverished grain processors in China, and so Chinese plants are pretty keen to make it.
Melamine is produced in a chemical plant—in China, usually in a urea fertilizer plant under the chemical industry bureaucracy—using a relatively sophisticated process. Some of it is used as a fire retardant or fertilizer; most of it is shipped to plastics plants, where it’s polymerized with formaldehyde and turned into products like disposable plastic cutlery.
I’m pretty sure that both these products—relatively valuable and meant to be free of contamination—are bagged on site where they are produced. It’s quite unlikely that they would be shipped in bulk by rail car or, even if they were, that wheat gluten would end up in a chemical bulk car and get contaminated.
So, finding melamine in your wheat gluten is like opening your box of corn flakes and finding a fistful of moonrocks inside. It could happen—apparently it did happen—but it doesn’t seem likely.
I do have a theory.
There is one common thread between wheat gluten and melamine:
Water.
Wheat gluten production uses a lot of water. After the wheat kernel is broken up in the dry mill, a water wash separates the insoluble wheat gluten from the soluble wheat starch. Then the globs of wheat gluten are screened off and go through a drying process. Any insolubles in the water could be concentrated in the gluten.
The melamine production process happens to produce a lot of melamine-laced effluent water.
Melamine has low solubility in water, biodegrades poorly, and tends to hang around in the environment.
For the purposes of my theory, it is highly advantageous that upriver of Binzhou is the Shandong Mingshui Great Chemical Group, whose urea plant--one of China’s ancient, 1958 vintage demonstration plants-- also produces melamine.
I must now hasten to add that I do not know about conditions at these two plants. I don’t know if the two plants share a water source, if there are significant quantities of melamine in Mingshui’s effluent, or how the wheat gluten plant in Binzhou treats its incoming process water.
But right now, I’d say that the theory of impurities in the wheat gluten through use of melamine-contaminated process water looks as good as any.
(an expanded version of this post is at China Matters, the Asian affairs website)