Protein Products Vulnerable to Amino Acid Spiking

Protein is having a “moment”-and a very good moment, at that. Unlike carbs, which have come in for all manner of criticism, or fat, which is going through its latest round of reputational reassessments, protein stands alone as the “virtuous” macronutrient: no mere repository of empty calories or artery-clogging lipids, but Nature’s ideal source of energy, satiety, and muscle-building amino acids.

Yet the shine on protein’s healthy halo could turn to rust if an insidious practice known as amino acid spiking persists. For when consumers purchase a purportedly protein-packed product that’s actually been spiked, they’re literally not getting what they pay for. And there’s no better way to lose consumer confidence-or the potential to profit from protein’s promise-than to say one thing on the label and deliver something far less impressive in the bottle, bar, tub, or packet.

The Body’s Building Blocks

To grasp just how high protein’s profile is flying these days, you need look no further than the results of this year’s International Food Information Council (IFIC) Food & Health Survey, in which fully 50% of respondents claimed they were either aiming for a certain amount of dietary protein, or were simply trying to get as much of the stuff as possible. And taking a look at the product-development side, researchers at Innova Market Insights tracked a 16.4% compound annual growth rate from 2009 to 2013 in new food and beverage launches in the United States that make a protein claim.

Far from being an empty trend, protein and its benefits are well substantiated. As Nandakumara Sarma, PhD, director of dietary supplements, US Pharmacopeia (USP; Rockville, MD), says, “The human body needs a certain amount of protein to cover not only its caloric needs but also its need for essential amino acids, which the human body requires but cannot make and, hence, must get from the diet.” The body then uses those amino acids to build proteins that participate in nearly all functions of the human body, Sarma says. Muscles, antibodies, enzymes, and more: they owe their existence to protein, as do we.

The Protein Premium

And we’re catching on to that fact. Everyone, from millennials and boomers to body-builders and big losers, now recognize protein as essential to sustaining energy, maintaining and growing muscles, even putting the kibosh on hunger pangs through its effects on satiety. Armed with this knowledge, consumers are paying a premium for supplements and functional foods that pack protein in-and proclaim it on the package.

Nowhere is this clearer than in the beverage sector. Innova found that products in the weight-management and sports-nutrition sub-categories can carry upwards of 40 g and 50 g of protein per serving, respectively, while averaging a respective and more reasonable 32 g and 18 g. And when the research firm looked solely at milk-based drinks-ready-to-drink (RTD) or powder-it found that those making high-protein claims fetched a 66% price premium over their mainstream counterparts.

Incentive to Increase

Such comfy margins give manufacturers every incentive to pump as much protein into their formulations as their budgets and product constraints will allow. But even when limited in their ability to add more protein, at least some processors appear willing to make it look as though they did. And that’s where amino acid spiking comes in.

“Amino acid spiking is not new and has certainly been reported in the past,” says Markus Lipp, PhD, senior director of food ingredients at USP. “It is hard to tell how widespread it is, as, of course, it is done in secrecy and with attempts to evade detection.” But whatever its prevalence, its motivation lies in the tension between the price that protein-packed products can capture and the equally dear price that manufacturers must pay for the protein ingredients to make them.

Or, as Lipp explains, “When amino acid spiking is done, a more expensive ingredient is…replaced with a lower-cost one, financially benefitting perpetrators.” More specifically, instead of building a protein powder entirely out of biologically valuable protein, “spikers,” so to speak, dope their formulations with cheaper, less nutritionally and physiologically beneficial substances like free amino acids.

Indeed, says John Travis, senior research scientist, NSF International (Ann Arbor, MI), “We suspect that the problem of protein or amino acid spiking was exacerbated by the increasing price of whey protein”-which, Innova notes, is the most sought-after protein in sports-performance and weight-management drinks. Whey protein isolates (WPIs) enjoy substantially higher penetration in sports beverages, whose consumers shell out for the “purest” form of protein.

Spiking to the Test

Pure protein is what consumers deserve to get. But when processors pull the bait-and-switch of spiking with non-protein amino acids, they’re taking consumers for a ride.

How do they get away with it? By exploiting a quirk in the method used to determine the protein content of foods, beverages, and dietary supplements. Called the Kjeldahl method, this procedure is what Sarma terms “a surrogate test,” in that it measures the total nitrogen in a test substance and uses that as an indicator of the protein present. “Typically, the numerical result for the amount of nitrogen is simply multiplied by the factor 6.25,” Sarma says. “The resulting figure is used as the amount of protein.”

But surrogate analyses fail to catch spiking thanks to two faulty assumptions that “some labs or companies intentionally or unintentionally make,” Travis says. The first is assuming that other compounds in the sample don’t contain nitrogen. “And two is [assuming] that nearly all of the nitrogen in the ingredient or product is present as protein,” he says. But several non-protein nitrogen-containing compounds-or NPN-can skew the nitrogen level upward, “artificially inflating the protein number,” he says.

The most common are amino acids. “For instance,” Travis says, “lysine and glycine have a higher nitrogen content than protein, both are less expensive than whey protein, and both may be commonly added to protein powders.” He also cites the melamine scandal of a few years back as an instance in which dubious processors added melamine-extremely rich in nitrogen-to pet food and infant formulas to boost protein analytics. Other ingredients can serve as go-to NPN sources as well, including taurine and creatine, which, Travis says, “are both commonly added to protein formulas.”

Catching Cheaters

Which raises the question of who would make such a deceptive formulation decision. And as far as Lipp is concerned, “It can only be done by people who lack the ethical boundaries, have access to the supply chain of proteins and cheap amino acids, and have access to a process to adulterate the protein with such an amino acid.”

Travis takes a more nuanced view, seeing “spikers” as falling into two camps: “1) those who intentionally formulate their ingredients or finished products with NPN sources to inflate the protein content number artificially, and 2) unintentional spikers using the non-specific test methods without knowing that further calculations are necessary to label an accurate protein content.”

Many in industry don’t realize that surrogate analyses such as Kjeldahl are only the first step in the process, Travis says. To get an accurate reflection of a product’s actual protein content, we must first correct for the presence of any NPN by subtracting it from the Kjeldahl results. “From a laboratory’s perspective, the issue becomes even more complex,” Travis continues. “A lab may run a free amino acid test, which finds nitrogen contributed from free amino acids like lysine and glycine. Subtracting this number from total nitrogen will give you a more accurate measure of nitrogen from protein only, but it does not account for other NPN like creatine and taurine. One can see how complex this becomes. At what point does the lab stop searching for NPN in an ingredient or product?”

Perhaps when they have an alternative to the Kjeldahl method for finding it. And according to Gabriel Giancaspro, PhD, vice president for food ingredients, dietary supplements, and herbal medicines at USP, pressure to identify such alternatives has directed attention to amino acid profile as one of the potential solutions. Instead of measuring “the simple nitrogen atom as ammonia, several techniques intended to measure proteins are based on protein hydrolysis and subsequent measurement of the released amino acids,” Giancaspro explains.

While this lessens the incentive to add, say, melamine as a source of simple nitrogen, adulterators may still be tempted to spike with the amino acids that the tests are designed to detect. “However,” Giancaspro continues, “spiking with pure amino acids to boost the protein content does not make much economic sense because production of pure amino acids is usually more expensive than production of nitrogen-rich ingredients.” One exception, he notes, occurs when a test looks for a particular amino acid. This is the case with the Lowry method, for instance, which zeroes in on tyrosine content. Thus, in this case, he says, “spiking with tyrosine could make economic sense, as you know your buyer is testing by Lowry.”

Spiking with amino acids from hydrolyzed proteins “is more likely to occur as economically motivated adulteration,” Giancaspro concludes. And some unlikely amino acid sources might even include hydrolyzed leather, which he calls “a typical adulterant.” To ferret out such shenanigans, he suggests denaturing the proteins with trichloroacetic acid (TCA), precipitating the free amino acids and more water-soluble peptides and then filtering or centrifuging them out for analysis. “Another analytical solution,” he says, “would be to use techniques that measure intact proteins, such as electrophoresis or isoelectrofocusing, or techniques that focus on the petidic bonds themselves, like BCA”-bicinchoninic acid assay-“or biuret.”

A Losing Game

Clearly, it’ll take some analytical innovation to beat the cheaters. Meantime, both consumers of protein products and such products’ well-intentioned manufacturers are left wondering what they’re getting. “In the most immediate sense,” Travis says, “spiking protein content provides ‘bad’ players with a temporary competitive edge and increased profit margins.” But in the longer term, he says, “Fraud by just a few bad companies has the potential to erode consumer confidence in supplements altogether, lumping the good companies in with the bad.”

And that, experts agree, is the real danger. As Sarma notes, “Victims are, of course, consumers, as they are buying a fraudulent product that is not what it purports to be. Ultimately, consumers, industry, and regulators will suffer from a loss of trust in the supply chain.”

As that chain grows ever more global, the chances to jeopardize trust multiply in tandem with those for spiking product. That, Travis says, is “the challenge of a complex global supply chain.” Protein spiking “can happen anywhere along it. It could be the formulators, ingredient suppliers, or the finished-product manufacturer. There are many opportunities for mistakes or economic fraud.”

Reinforcing the Supply Chain

Thus, he says, each link needs targeted and rigorous supplier qualification programs reinforced through testing. “Retailers in particular have looked to third-party product testing and certification to ensure the quality and safety of the supplements on their store shelves,” he says. To comply with GMPs, manufacturers must test incoming ingredients and finished products to confirm both their identity and accordance with specifications like protein content. Failure to test incoming ingredients, Travis adds, is “the most-cited GMP nonconformance by FDA auditors.”

When NSF International tests products to validate protein content, he continues, “we run a total amino acid scan as well as a free amino acid scan, then subtract the two numbers to get an accurate protein number. This means that we eliminate the nitrogen that is contributed from all non-protein compounds such as creatine, taurine, melamine, urea, ammonium sulfate, et cetera.” The organization also participates in industry discussions about testing and offers guidance on proper supplier validation and protein determination.

And a good thing, too, considering that regulatory oversight of protein-content determination remains frustratingly lax. As Andrea Wong, PhD, vice president, scientific and regulatory affairs, Council for Responsible Nutrition (CRN; Washington, DC), points out, “Currently, FDA’s labeling regulations do not specify what should or should not be counted toward protein content.” That helps explain why CRN released its own protein calculation guidelines for use with supplements and functional food and beverages.

CRN’s guidelines recommend that content determinations include only proteins that, “by definition, consist of a chain of amino acids connected by peptide bonds,” according to a press release. And while the organization recognizes that NPN ingredients may have nutritional and physiological benefits themselves, Wong says, “it is important that they are labeled appropriately and not be included in the protein count.”

Wong says CRN has “received enthusiastic support of our protein labeling guidelines from industry, health professionals, and consumers,” adding that the guidelines comport with those issued earlier by the American Herbal Products Association (AHPA; Silver Spring, MD)-not surprising considering that the two groups cooperated to provide consistency and make it easier for industry members to voluntarily comply with both programs.

As Michael McGuffin, AHPA’s president, says, “The AHPA Guidance on Labeling of Protein in Food and Dietary Supplements creates a standard by establishing that protein is calculated to include only proteins that are chains of amino acids connected by peptide bonds and to exclude any non-protein nitrogen-containing substances from such calculations.” He adds that the guidance highlights industry’s “ability to identify an issue and collaborate to develop an effective solution.”

And that should put manufacturers’, not to mention consumers’, minds at ease. As Travis points out, “There will always be economic fraud where money is to be made, which is why transparency is so important to consumers. Doing your due diligence to identify a high-quality, accredited laboratory to conduct your ingredient testing is essential, and relativity simple if you know what to look for and which questions to ask.”

Photo ©iStockphoto.com/Alasdair Thomson