Nature’s Barcode

As the trends of all-natural, grassfed and organic beef sweep the marketplace, consumers’ growing concern for the origin of their food is evident. Many consumers wonder if it is possible to validate claims of organic or grassfed.
Recently, a company known as Picarro, maker of high precision gas analyzers, in cooperation with IsoForensics, Inc., developed an inexpensive, easy-to-use and portable analyzer for elemental isotopes to determine exactly where food comes from.
This technology uses isotope signatures to determine the region of origin and composition of many agricultural products.
Each element on the periodic table is composed of three basic sub-atomic particles: protons, neutrons and electrons. The mass, or weight, of any given element depends on the number of protons and neutrons present. Isotopes are forms of the same element, differing only in the number of neutrons.
Lesley Chesson, Analytical Chemist at IsoForensics, Inc., explains, “The addition of the neutrons gives different masses to the elements.” Higher mass means these isotopes are heavier.
Each element naturally occurs as many isotopes. Across the country, different ratios of these isotopes are present. Abundant isotopes, such as Carbon-12, compose much of the atmosphere and are not particularly useful for analytical purposes. However, some isotopes are considered rare and exist only in very small quantities. These stable, rare isotopes, such as Carbon-13, are measured and compared to known values across the country to predict origin or diet.
To detect the rare isotopes, Chesson explains, “We just measure mass differences and how much of the rare isotopes end up in the sample.”
The isotope signature describes what percentages of rare isotopes exist in a sample, and can be compared to known isotope signatures across the country.
Alex Salkever, Director of Marketing at Picarro, says, “The two molecules that we are looking at primarily are carbon and water.”
Chesson further says, “We call carbon and nitrogen the dietary isotopes, and they yield information about what animals have eaten. Oxygen and hydrogen are linked to water, and from that we can get more origin information.”
IsoForensics, Inc. developed a series of maps using prediction models to accurately estimate the origin of milk by using hydrogen and oxygen isotopes.
“We don’t mean that we have collected a sample from every state, or everywhere in the U.S.,” says Chesson.
Rather, the maps are based on understanding the relationships and mechanisms distributing isotopes across the region. She further explains the method isn’t zip code specific, but can be used to identify broad regions.
Chesson describes how they use hydrogen and oxygen to create maps, saying, “Water reacts differently during evaporation and precipitation. Lighter isotopes evaporate first because they don’t weigh as much. As the cloud moves inland, and it begins to cool down and rain, the heavy isotopes will rain down first.”
As rain continues, lighter isotopes of hydrogen and oxygen in water are distributed to higher elevations across the United States.
The Milk Origin Verification Solution (MOVS), a cooperative effort by Picarro, IsoForensics, Inc., and the University of Utah, kicked off a new isotope analysis project about a year and a half ago, and, according to Salkever, “It started as a business venture with IsoForensics as an effort to commercialize isotope analysis as a method for origin tracking and food adulteration.
In the MOVS project, researchers analyzed water extracted from milk samples from around the country. Analysis of hydrogen and oxygen isotopes showed correlation between the drinking water for cows and milk, allowing scientists to predict the origins of milk.  
While widespread isotope analysis for applications of food origin is a relatively new technology in the United States, the European Union uses the technology for a variety of applications.
“The classic example of this technology is being used in wine,” says Chesson, referring to wine origin databases. It has also been used to thwart re-labeling of agriculture products, such as butter, in attempts at tariff evasion.
The applications of isotope analysis extend to nearly every food product. Chesson lists honey, milk, beef and even soft drinks as common targets of isotope analysis for confirmation of origin.
“If you can name a food, isotope analysis has probably been done on it,” says Chesson.
Current applications of isotope analysis focus on use of carbon isotopes to determine whether cattle are grassfed or corn fed. As per the common phrase “you are what you eat,” muscle in cattle forms in the same isotopic ratio of carbon as is consumed by the animal.
“When a cow is fed corn, it has a very different isotope signature than when it is fed grass,” explains Salkever. He further clarifies, “Grass, because of the way it photosynthesizes and the way the plant develops, pulls in a specific ratio of Carbon-12 and Carbon-13 atoms. Corn will show a different signature of Carbon-12 and Carbon-13 atoms.”
Meat analysis determines whether the animal ate grass or corn.
“We can burn a sample of meat, push the CO2 into our analyzer and look at the ratio of isotopes,” Salkever explains. The resulting data allows scientists to determine whether an animal has been truly grassfed.
One particular study by L.A. Martinelli in Brazil compared beef origin in a study of McDonalds Big Mac hamburgers. Not only did the beef from Big Mac patties correspond with the source of beef for McDonalds restaurants around the world, the distribution of carbon and nitrogen isotopes were unique and identifiable, verifying the ability of isotope analysis to predict where cattle were raised.
This new technology allows consumers to affirm claims made by retailers about all-natural and grassfed beef, and IsoForensics, Inc. provides the opportunities for consumers to do just that. By sending in samples, IsoForensics, Inc. tests various agricultural products, determining origin, adulteration or diet.
“It’s not like an RFID tag or barcode. The isotope signature cannot be changed,” Salkever says, in speaking about the importance of isotope analysis.
Essentially, nature provides its own bar code. Verifying organic or grassfed claims prior to isotope analysis was all but impossible. Labels can be easily swapped and even tags can be removed, but isotope analysis always tells the truth.
For specialized beef producers, the opportunity to verify their products to consumers as truly grassfed or organic is incredibly important. Validating these claims gives customers an additional sense of security about their food source, and isotope analysis techniques offer producers limitless applications.
“You can certainly double check feeding practices,” says Chesson, “among other things.”
Consumers’ constant search for safe beef is ongoing. By providing the opportunity to verify the origins, consumers gain a sense of reassurance about the meat commercially available. Isotope analysis provides one avenue to finally verify claims of organic and grassfed beef.
Saige Albert is assistant editor of the Wyoming Livestock Roundup and can be reached at saige@wylr.net.