In a continuing endeavor to help the dietary supplements industry agree on and evaluate analytical methods to ensure quality, safety and regulatory compliance, a task force spearheaded by AOAC INTERNATIONAL has picked six more ingredients for evaluation, beginning this month (March). The ingredients are the latest in what will eventually be a set of 25 “priority ingredients” to be evaluated by the 131-year-old analytical chemists’ organization under a contract funded by the National Institutes of Health’s (NIH) Office of Dietary Supplements. (For further reading, see “Ingredient Authentication in the Lab,” in Nutraceuticals World’s January/February 2016 issue.)

Rather than dictating the ingredients by fiat, NIH and AOAC delegated the task to an advisory panel for AOAC’s Stakeholder Panel on Dietary Supplements, which chose the latest batch during a Dec. 6 meeting in Rockville, MD. “They’ve created a very democratic process where they get input from regulators, policy makers and industry,” said Duffy MacKay, ND, senior vice president for scientific and regulatory affairs at the Council for Responsible Nutrition, Washington, D.C. “They are trying to fill gaps for methods that the industry can use to make sure ingredients are what they say they are and meet their specifications.”

An Analytical Process
Priority ingredients are picked on the basis of such factors as market importance, adulteration risk, attention from ongoing clinical trials and toxicological concerns, said Steven Dentali, PhD, a pharmacognosist and research fellow, Botanical Development, at Herbalife International, who also sits on the advisory panel.

The six newly selected priority ingredients reflect exactly these types of concerns. They were chosen in two batches, one of which will be brought before AOAC’s midyear meeting, March 14-18 in Gaithersburg, MD, and the other at its fall annual meeting, Sep. 18-21 in Dallas, TX.

At each conference, working groups will be formed for each of the ingredients being brought before that meeting. These working groups will develop specifications called standard method performance requirements (SMPRs) for what a method for each ingredient must accomplish. Candidate methods will then be solicited for each ingredient for later evaluation by expert panels convened to see if they meet the SMPRs.

Methods these expert panels approve of will be designated as “first action” official methods—something that is very important to the industry, because AOAC official methods are widely viewed as the gold standard of analysis by regulatory bodies around the world. After a few years in use, these methods may then advance to “final action” status—but for regulatory and industry purposes, first action and final action methods are both considered as official. “With AOAC, the value is having a method that is accepted universally,” Dr. Dentali said.

The three ingredients to be considered in March include aloe vera (polysaccharides), vitamin B12 and protein. Those to be considered in September are ginger, vitamins K1 and K2 and free amino acids.

In choosing these, Dr. Dentali noted, the panel did a good job of balancing competing needs. In each group, he said, “there’s a vitamin, a protein and a botanical.” Not surprisingly, they are each of significant concern to major portions of the dietary supplements industry.

Ingredients Under Review

Aloe Vera
Aloe vera juice is a product that has risen from obscurity to become so popular that in February 2015, Prevention magazine devoted an entire article to the question: “Why Is Everyone Suddenly Drinking Aloe Juice?” Academy Award winner and food writer Gwyneth Paltrow has also been promoting it.

At the same time, the National Toxicology Program (NTP) has found that “nondecolorized” aloe vera causes colon cancers in rats. Among other concerns, this raises the specter of aloe vera being listed as a “known carcinogen” under California’s Proposition 65, which recognizes NTP’s findings as authoritative.

The aloe vera formulation studied by the NTP, however, isn’t the product used in the aloe beverage industry. It was made from a combination of the aloe vera leaf’s interior pulp and its green rind, which contains a strong laxative chemical that the industry doesn’t want in its products anyway. Aloe-juice products are made either solely from the pulp or from whole leaves that have been through a purification process known as decolorization. “What NTP tested is very different from what people are using in the marketplace,” Dr. MacKay said.

NTP’s deputy program director for science, Dr. Nigel Walker, also appears to recognize that this is an issue. In comments posted to the agency’s website, he noted that NTP needs more information to determine how its findings translate to human risks. “We particularly need to know what are the constituents [and] what’s the level of those constituents in human products,” he said.

“That’s where AOAC comes in,” added Dr. MacKay. “The way the aloe industry is going to move forward is proving it doesn’t have this component.”

In fact, the search for tests for this substance, called aloin, is already under way; a call for methods was issued in September 2015 and submitted methods will be reviewed by an expert panel at this month’s mid-year meeting.

But what the stakeholders panel decided last fall is only half of what’s needed. As long as aloe vera is under the microscope, there’s also a need for official methods to measure its polysaccharide content, which Dr. Dentali described as a commonly accepted measure of quality.

Thus, even as the hunt for official methods for aloin will be winding down in March, the search for official methods for polysaccharides will be ramping up. Ultimately, the result will be a one-two punch, with one method (or methods) to address safety and another (or others) to address quality.

Vitamin B12
In this case, the need is simple, but urgent. In recent years, there’s been a dramatic increase in products, especially energy drinks, fortified with high levels of vitamin B12. Official methods exist for such uses as determining B12 levels in infant formula and adult nutritional foods, but they may not be applicable to today’s exploding energy-drink market. “There aren’t good methods for all the different products out there,” said Dr. MacKay.

Protein
The current method for protein analysis is the Kjeldahl method, which dates back to the early 1880s. It involves mixing the sample with sulfuric acid and heating it to convert its nitrogen into ammonia. Measuring the ammonia then reveals the amount of nitrogen in the original sample. From that, the protein content can then be calculated.

It’s a long-established test, but it can be fooled by adulterating the product with other sources of organic nitrogen to the product, as happened in the 2008 Chinese melamine scandal. But the added chemical needn’t be toxic. The test can also be fooled by adding inexpensive amino acids to products supposedly containing high-quality proteins like soy or whey—a particular concern in today’s burgeoning protein-beverage market.

The problem is called “protein spiking,” according to Dr. MacKay, who explained that it artificially inflates the ingredient’s apparent protein content. “The problem is there’s no easy test to differentiate nitrogen bound to the protein from other sources of nitrogen.”

What’s needed is a new method capable of distinguishing proteins from free amino acids or other nitrogen-containing adulterants. It’s particularly pressing, Dr. Dentali said, because protein meal replacement drinks are extremely popular—both among body builders trying to gain weight, and dieters trying to lose it. “Meal replacement beverages are a big deal,” he added.

Free Amino Acids
This is simply the flip side of the protein problem. “They are looking for two methods to distinguish native proteins or things derived from native proteins from things added via amino acids,” Dr. MacKay said.

Vitamins K1 & K2
Vitamin K2 is an isomer of vitamin K1 that some think is more helpful for bone health than K1. “Vitamin K2 is becoming increasingly viewed as important,” Dr. Dentali said. “I take it for supporting calcium absorption.”

But it is also more expensive, raising concerns that unscrupulous suppliers might try to substitute the cheaper version. What’s needed is a test to differentiate vitamin K2 from vitamin K1, Dr. MacKay said.

Ginger
Ginger is a well-known spice whose active ingredients, known as gingerols, may also be potent anti-inflammatories. That makes it important to have a test that confirms that products claiming to contain ginger actually do.

Also, a 2012 study published in the Journal of Agricultural Food Chemistry found that gingerols and their dehydration products shogaols easily decompose during processing and long-term storage. “We are not taking [this] seriously enough when we quantify ginger components in ginger extracts and commercial ginger products or supplements,” said the study’s lead author, Shengmin Sang, PhD, lead scientist for functional foods and bioactive compounds at North Carolina Agricultural and Technical State University, Kannapolis, NC.

“There are methods in the literature,” Dr. Sang added. “However, there is no comparison of the accuracy of each method.”

Open Participation
For those interested in participating in the process, it’s not too late to attend the March meeting or volunteer for a working group or expert review panel. Registration for the meeting stays open until one week in advance, and participants don’t need to be an AOAC member to participate. “The process works best when we have the right people in the room,” said Dawn L. Frazier, CAE, who heads AOAC’s scientific business development outreach efforts for dietary supplements. For more information e-mail dfrazier@aoac.org, or visit www.AOAC.org and click on the Standards Development tab.

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Portland-based freelance writer Richard A. Lovett is a former law professor, PhD economist, and one-time astrophysicist who has written hundreds of articles for such publications as Nature, National Geographic News, Scientific American, Science, New Scientist, and Cosmos. He is also an award-winning science fiction writer, sports writer, and has coached three women in the U.S. Olympic Team Marathon Trials.