Tuesday, May 01, 2007

EAT ZINC: American's will buy anything, right?

White powder, looks clean -- hard for Americans to tell from protein, maybe? Or just a trace element source?

"Xuzhou Anying Biologic Technology Development Co. and Binzhou Futian Biology Technology Co., the two companies under investigation by Chinese and U.S. officials, sell vegetable proteins on Alibaba," wrote reporters at the Washington Post today.

And if you read your GlobalSecurity.Org Senior Fellow's blog yesterday, you know Xuzhou Anying also sells zinc oxide, right along side its protein powder, fresh carrots and ginger!

The issue becomes still more clouded when one finds zinc oxide poisoning causes renal disease in cats!

Traditionally, the poisoning comes from the eating of pennies, which are mostly zinc.

However a number of veterinary entries here and here implicate some other household materials containing zinc oxide.

The Merck Veterinary Manual indicates the median lethal dose in animals is approximately 100 mg / kilogram. It's a substantial amount. "Also, diets containing high levels of zinc (>2,000 ppm) have been reported to cause chronic zinc toxicosis in large animals," it reads.

Now, let's review.

It's not intuitively obvious, to someone with a Ph.D. in chemistry -- me, why zinc oxide, an inert compound used in paints, sunblock, rubber manufacture and baby powder, would be sold by a company marketing food additives.

That is, until looking belatedly at pet food labels, where zinc oxide appears to be in brands in extremely small amounts. The amounts appear to be so small as to be contaminants. They are not quantitated on the package.

For example, on the bag of Hill's Science Diet in DD's kitchen, the fine print reads "minerals" which include, in parentheses -- ferrous sulfate, zinc oxide, copper sulfate, manganous oxide, calcium iodate and sodium selenite. However, most of these compounds aren't even listed in the "guaranteed analysis," which quantitates only amounts (0.6 percent) of calcium.

Indeed, there's no need for any diet to include copper sulfate, to mention one compound. One suspects that might just as well come from extremely trace water contaminations. Since a form of copper sulfate appears to be used as a fungicide in crops, and has received an exemption from the Environmental Protection Agency here, it's possible it is included because it is a contaminant, along with the other materials listed.

Now, while zinc ion is a key component in metalloenzymes, critical proteins in the metabolic pathways of humans and animals, one does not eat zinc oxide to furnish it.

Zinc oxide is not soluble in water like the form of zinc which one acquires naturally in the diet. It is soluble in acid, so presumably stomach acid -- HCl -- may make it available. However, this still appears to make no sense from a biochemical and nutritional standpoint.

To explain further, DD once purified and characterized a metalloenzyme found in wheat germ, bought at a health food store, which required zinc for its activity. But the amount of zinc present was vanishingly small.

People and animals don't need to consume any special dedicated zinc compound at all.

For example, red meats -- or even wheat germ, naturally furnish the zinc needed by metalloenzymes.

(See NIH explanation here. By reading, let's repeat again, one can see adults need only vanishingly small amouts of zinc, coming naturally in red meat and poultry, and certainly not from the consumption of zinc oxide.)

In unusual circumstances, "Pharmacological doses of zinc may be beneficial in some circumstances and harmful in others," reads a summary from an National Institute of Health conference on its potential use in dietary supplements.

Now perhaps this is all coincidence.

Xuzhou Anying announces on its website that "Zinc oxide is easier to be absorbed by animal than other zinc." It is an empty phrase -- complete rubbish -- a sales push to get feed buyers apparently interested in purchasing zinc oxide.

Because it is known that the Chinese tweak additives into food powders to boost their selling price, it would seem something worth checking, if only so that it can be ruled out as a source of trouble.

After all, what has killed pets? Melamine is thought to be the primary agent. But melamine is, according to news reports, said to be only slightly toxic.

What's the truth of the toxicity? Are there combined actions at work? A stupid and bad formulation? DD doesn't know.

But the Washington Post also writes, "Before melamine there was urea, Chinese traders said -- another nitrogen-rich chemical that was used to give false high scores on tests of protein content but was abandoned after it made animals ill."

(The original is here.)

Oh well, urea!

DD worked has worked with urea many times and never thought of it as a food. No one sane would eat urea. Urea did, however, indeed put assays for protein through the roof.

Now what might one use "zinc oxide of feedstuff" -- which is what it is called by Xuzhou Anying -- for? To add to animal feeds? Why do animal foods which already contain materials that naturally would have trace elements of zinc in them need more zinc from zinc oxide?

Good question? Ask the FDA.

"The task of guarding against contaminants in imports has become far more complicated because an increasing portion of the tens of billions of dollars in Chinese food and agricultural imports involves powders and concentrates for the processed-food industry -- including the wheat gluten and rice protein at the center of the pet food scandal," writes the Post.

And yet wheat gluten, rice protein and other plant protein extenders are not special commodities. They can easily be made in the United States.

However, somewhere along the line, for the sake of the global market, bad business decisions were made. These bad decisions resulted in the ceding of animal feed supply chains to untrustworthy partners. In this, companies like MenuFoods, ChemNutra, Wilbur-Ellis and other American partners cannot evade responsibility. Decisions were made which resulted in egregious breaking of faith with the American consumer.

And, although newspaper journalists have been loathe so far to dig into the ethics of it, the decisions would have had to have been based on the fact that profits could be saved by dealing with the Chinese vendors, an industry with no regulation and apparently no scruples at all.

The questions raised by today's lines of reasoning are legitimate ones and they should be answered as fast as possible as the FDA goes about its business of investigating ChemNutra, MenuFoods, Wilbur-Ellis and all the Chinese agencies that are part of the chain which caused the introduction of tainted pet food into North America.


Your GlobalSecurity.Org Senior Fellow is astonished anyone would consider urea as an additive to food. However, it appears to be the grandfather adulterant from which the idea of using melamine descends. See here.

Urea was a common chemical in protein biochemistry labs DD worked in. Furnished by JT Baker and other makers of finely purified chemicals, one had to be careful to either keep it out of, or remove it from -- buffers, reagents and preparations. This was because it interfered with general protein determinations. In other words, it made you look like you had a lot more protein on hand that was actually there. In the lab, urea contamination -- when it occured -- was always fairly obvious.

But no one was optimizing the use of it to pooch testing.

In 1985 a criminal agricultural enterprise in the United States added urea to wheat to boost general nitrogen determinations and profit.

A tipster on the inside informed the government and the FDA raided the operation.

"The investigators spent a day and a half on the premises," reads a newstory on the incident here.

"During that time, they collected wheat scrapings from one of the grain dryers that FDA lab analysis later revealed contained as much as 33 percent urea. During the next 10 days, FDA investigators took wheat samples from local farm bins where Schuler [company] wheat was stored. One percent of urea was found in some of the wheat ... As a result of FDA's investigation, during October and November 1985, U.S. marshals seized three bins and 26 railroad cars of wheat in the St. Paul-Minneapolis area and three barges of wheat--two in New Orleans and one in Chattanooga--bound for foreign ports."

"The urea did not pose a health hazard [it was said] because there is no known toxic effect of 1 percent levels of urea in food," reads the piece. "Urea is currently approved by FDA as an additive in yeast used for baked goods and alcoholic beverages."

JT Baker's toxicity spec sheet on urea.

Related links:

The latest in 'EAT ZINC!' -- Zinc salts in animal feeds and fertilizer.

Eat Zinc Oxide! From yesterday.

ChemNutra's PR blog. Tracks articles on the pet food spiking implicating Chinese practice.

Earlier piece on tainted pet food for this blog.

Incidental agroterrorism.

[This article has been updated from an earlier version.]


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