To Be or not to Bee?
Honey, Forensics, and the BP Oil Spill
Of all the immortal phrases taken from Hamlet, “To be or not to be” triumphs as the most famous. Why? Because identity crises spread far and wide, beyond human self-doubt and into just about every other realm. Consider the most basic crisis of identity: distinguishing a truth from a lie. The difficulty of the task varies drastically. For instance, it’s easy to see through a friend’s assertion that she met Jay-Z at McDonald’s and went for a spin in his ‘rari. It’s not so easy to, say, substantiate a company’s claim that the product they sell is natural or call bluff on BP’s statements concerning the extent of the 2010 oil spill.
Everyday we are confronted with claims we cannot substantiate.
In the 1980s the baby food company Beech-Nut advertised an apple juice that had “no sugar added” and was “100 percent juice.” To the shock and anger of their customers, the news broke that the apple juice was actually, in the words of Beech-Nut’s own employee, a “chemical cocktail.” The mixture contained 0 percent apple product, artificial ingredients, and a whole lot of sugar additives. As a result, two executives were convicted on 300+ counts of violating the Food, Drug, and Cosmetic Act, including conspiracy, mail-fraud, and something along the lines of stealing candy from a baby.
Although eventually found out, Beech-Nut had successfully sold their adulterated product for ten years. This raises an important question: how do we know that what we’re consuming is what we think it is?
Randy Culp, Associate Director and Research Scientist at CAIS, explains that authenticating the naturalness of food products is a burgeoning field.
“I don’t think a day goes by that I don’t get an email from a company asking if we can isolate certain compounds because they don’t believe the material is the real deal. I think we’ve tested well over 1,000 different natural compounds used in the food and flavor industry,” Randy said.
That’s because desirable compounds like olive oil, coffee, spices, et cetera, are expensive to produce. Especially with the rising trend of health and environmental consciousness, companies are economically incentivized to falsely label their products as pure, all natural, or organic.
The FDA qualifies a product as ‘adulterated’ if a valuable constituent has been omitted or substituted partially or wholly, “if damage has been concealed, or if a substance has been added to increase bulk, reduce quality, or make it appear to be of greater value than it is.” For example, manufacturers may adulterate ground coffee by cutting it with twigs and leaves, which reduces the quality by half while simultaneously doubling its volume. Beech-Nut adulterated their apple juice by substituting key components of the product (such as apple) for lesser quality material like corn syrup and cane sugar. Other companies may add synthetic material or alter the composition of the product chemically.
To combat industrial dishonesty, CAIS compliments classical chemical techniques with isotope analysis to provide insight into a substance’s naturalness. Gas chromatography, mass spectrometry, or a combination of the two techniques followed by isotopic analysis, frequently reveals adulteration.
In classical chemical analysis, a gas chromatograph separates material into its individual constituents based on volatility. The mass spectrometer ionizes (or charges) a sample’s individual constituents and sorts them based on mass. The results from each test are delivered as spectra of relative abundance that, when compared to spectra of a control sample, identifies the elemental or molecular composition. A particular peak in the spectra may indicate that a component is derived from synthetic material or an unnatural process. A combination of GC and MS tests may reveal the presence or absence of specific biomarkers that suggest a component underwent chemical manipulation. Although these methods lend to the determination of a component’s naturalness, they do not provide a complete answer.
Here’s where isotopic analysis comes into play. We can tell a lot about a material based on the carbon isotopes and their relative abundance. Furthermore, the concentration of carbon isotopes and their ratios to one another reflect their environment of origin as well as their chemical makeup. Take plants as a case in point. Plants are differentiated into three types according to their methods of photosynthesis: C3, C4, and CAM. Each has a noticeably different ratio of mass 13 carbon to mass 12 carbon. Via isotopic analysis, scientists can reveal an unknown plant sample’s ratio of stable carbon isotopes to determine its authenticity.
A Surplus of Honey
This isotopic identity is called a “signature” or a “fingerprint.” The method applies very usefully to the honey industry. Currently, the amount of honey floating around the market exceeds the world’s supply, which indicates widespread adulteration. The problem is multifaceted. Misbranding, as Beech-Nut knows all too well, is illegal, but it also adds to competition. When the market is flooded with cheap substitutes disguised as honey, honest apiaries (bee farms) suffer.
To protect the rights of consumers and the economic interests of honest beekeepers, the FDA certified CAIS and one other lab to conduct analyses on imported honey in order to verify whether or not the honey has been adulterated. Honey is defined according to the FDA as “a thick, sweet syrupy substance that bees make as food from the nectar of flowers and store in honeycombs.” Manufacturers commonly use cane sugar or corn syrup to bulk up their product. These additives derive from C4 plants, the carbon isotopic ratio of which differs from the flowering plants that produce nectar. Through isotopic analysis, CAIS can identify the phonies from the real-deal when the adulterant is a C4 derivative.
But some manufacturers have caught on to the isotopic trail that their C4 additives leave. Instead, they may use cheap beet sugar derived from C3 flowering plants, which, upon isotopic analysis, would not be distinguished from the nectar that also derives from C3 flowering plants. The latest method of the Association of Official Analytical Chemists is to extract protein from the honey and compare it to the sample’s sugar. Protein derives from the bees’ enzymatic breakdown of pollen and nectar. If the given honey sample is pure, the carbon isotope value of the protein and of the honey should be virtually identical.
Even this method isn’t quite adequate. Randy is currently working with the UGA Honey Bee Program to test the application of other isotopic ratios, including hydrogen, oxygen, nitrogen, strontium, and trace metals. The latter seems promising. Plants take up essential elements from their environment, which impart specific isotopic signatures that can point to geographic origin. If companies claim their honey comes from apiaries in Brazil but analysis of isotopes and trace metals shows a different geographic origin, scientists may assume the honey is not authentic.
Tracing Origins of H, C, and O
Let’s return to Hamlet’s soliloquy: “To be or not to be?” That is the question UGA research professor Mandy Joye and her team begged of an oil plume permeating through the floor of the Gulf of Mexico. Is it natural oil, which the Gulf regularly seeps out at high volumes, or is it oil from the BP wellhead that erupted in 2010?
Recall that the Deepwater Horizon disaster was the largest oil spill in history. The incident dealt severe damage, both observed and yet to be calculated, to the environment as well as the animals living on the Gulf shores and in the sea itself. While the government estimated the total oil released fell within a range of 4.2–4.9 million barrels, BP claims only about 3.1 million (values vary depending on secondary sources. It was surprisingly difficult to find a straightforward estimate from a primary source). BP further claims that all of the oil is accounted for and does not go beyond 2 kilometers around the wellhead. Dr. Joye, among other researchers, has found evidence that suggests the full extent far exceeds these limits.
Randy and other CAIS scientists helped Dr. Joye and her team to verify their findings by analyzing the isotopic composition of hydrocarbons. These compounds are the main constituents of petroleum and natural gas, and so show up in material that flows from a wellhead or seeps out of the seafloor. CAIS conducted analyses using GC-IRMS, which is gas chromatography in conjunction with isotope-ratio mass spectrometry. The GC separates the hydrocarbon into its constituents; the IRMS identifies the stable isotopic ratios of carbon and of hydrogen and compares them on a spectrum. As previously stated, biochemical and environmental factors influence isotopic ratios. So the GC-IRMS is a powerful tool used to trace the source of compounds at hand.
Results showed that the hydrocarbons Mandy sampled from the oil plume bore a unique signature similar to the oil produced from BP’s wellhead.
Scientists apply the same analysis in forensics cases. An example is the use of the isotopic ratios of hydrogen and oxygen. When a person drinks local water, the isotopic signatures of the water’s elements eventually show up in his or her hair. Let’s say someone from Georgia spent a few weeks in Rio de Janeiro and then made his or her way to Paris. Because hair grows about ½ inch per month, certain points of length in hair carry isotopic signatures of water from each of those places, provided that the signatures are distinct enough and the subject has consumed local water in these areas. Isotopic analysis can therefore help answer the whens and wheres in crime scene investigations.
“So you see why I’m still here,” Randy said. “It’s fun. And it’s challenging.”
In his 34 years at CAIS, Randy has seen the institution grow from a small research team with less than a dozen staff members into a diverse enterprise bursting at the seams with research, service, and educational outreach. The last four years saw a push to bring in more students — undergrads, grads, and post-docs — in order to spread awareness of the practical applications of isotopic studies. They are many, they are diverse, and they are growing.