Terpene Analysis Advancements: Reshaping the Future of the Cannabis Industry

The Intrigue of the Cannabis Plant Goes Deeper than You Think

The cannabis plant, my friends, is a marvelously complex subject, full of intrigue and mystery. Believe it or not, this humble plant boasts over 500 different chemical compounds! While you may be familiar with the likes of THC and CBD – the cannabinoids that are renowned for their euphoric and medicinal effects – there is so much more to explore when it comes to this wondrous herb.

Enter the terpenes, my dear readers. These essential oils are secreted by the same glands that produce THC, CBD, and other minor cannabinoids. They are responsible for the unique aromas that distinguish different strains of cannabis, and, like other plants, they have evolved to repel predators and attract pollinators.

Weather, climate, soil type, and other environmental factors all play a role in determining the terpene profile of a given cannabis strain. This means that each strain has a distinct scent and flavor profile, as well as its own unique medicinal properties.

Despite being non-essential to the survival of cultivated cannabis plants, terpenes are highly valued by consumers. The Blueberry and Lemon Haze strains, for example, are beloved for their distinct berry and lemon aromas, respectively.

But terpenes are more than just pretty scents, my friends. Some of them have been found to have significant medicinal properties. Linalool, for instance, is a primary terpene in cannabis that has potent anti-anxiety and sedative effects. Limonene, another major terpene, has been shown to be a powerful antidepressant.

Given the diversity of terpene expression in different strains of cannabis and the potential benefits they offer, it is essential to have reliable methods for terpene analysis. This is crucial for patients, sellers, and breeders alike.

Gas Chromatography as an Essential Method for Terpene Analysis

In the realm of cannabinoid analysis within the enigmatic cannabis plant, high-performance liquid chromatography (HPLC) reigns supreme, constituting nearly half of the total cannabis testing market. This esteemed technique is predominantly employed to ascertain the potency of specific cannabis samples or to generate comprehensive cannabinoid profiles of the plant. However, when examining terpenes, authorities in the field propose that an alternative method may prove more efficacious.

Terpenes, by their very nature, are notably volatile compounds, particularly when juxtaposed with cannabinoids. The most volatile terpenes commence evaporation at approximately 70°F, while THC—the principal target for potency analysis—boils at roughly 315°F. For such volatile organic compounds, gas chromatography is generally favored.

Gas chromatography enjoys widespread use as the preeminent analytical method for terpene analysis in both academic and commercial spheres. Dr. Cindy Orser, the esteemed Chief Scientific Officer of Digipath Labs in Nevada, asserts that “as terpenes contribute to the potency and sensory perception of cannabis, having a reliable and efficient analytical method for terpene analysis is of paramount importance.” Given the volatility of terpenes, gas chromatography is particularly well-suited for their examination.

The conventional approach to terpene analysis involves gas chromatography with a flame ionization detector (GC-FID). The initial step involves preparing a solvent-based extraction by immersing cannabis plant material in a liquid solvent—such as butane, propane, ethanol, or CO2—to facilitate the extraction of terpenes and cannabinoids into the solvent. Subsequently, the extraction liquid is introduced into the gas chromatography apparatus, where cannabinoids and terpenes are separated as they traverse the gas chromatograph. Lastly, the compounds are channeled to the flame ionization detector, where they combust over a heated hydrogen-air flame, generating organic ions. Electrodes within the FID then quantify the current generated by the ions, which, in concert with the retention time of the compound in the gas chromatograph, allows for the identification and quantification of the terpenes present in the sample.

Non-Destructive Analysis with Headspace Solid-Phase Microextraction

While GC-FID has been the tried and true method for terpene testing, there are some new kids on the block that are starting to make waves in the field of terpene analysis. Head over to academic circles, and you’ll see that headspace solid-phase microextraction (HS-SPME) paired with GC-mass spectrometry (GC-MS) is the latest cool kid on the block.

Now, what makes terpenes so ideal for headspace analytical methods, you ask? It’s because terpene compounds are highly volatile and have a high vapor pressure, making them perfect for analyzing the volatile components in the gas phase above the sample.

In HS-SPME, a special fiber containing a suitable stationary phase is inserted through the rubber septum of a headspace vial holding the sample. The fiber is held near the sample for a moderate amount of time, allowing the volatile compounds in the gas phase above the sample to cling to the fiber. The fiber is then inserted into the injection port of the GC-MS machine, where the volatile compounds are released and can be analyzed using the GC-MS apparatus.

Currently, GC-Headspace-MS is considered the top-dog in terpene analysis, allowing for peak identification and purity of terpene speciation in approximately 18 minutes. This method is quick and requires minimal sample prep, making it ideal for those in a hurry.

But that’s not all! HS-SPME with GC-MS offers several advantages over traditional methods. Unlike GC-FID analysis, HS-SPME with GC-MS is non-destructive, preserving the original sample without exposing it to any chemicals or requiring a solvent-extraction. This eliminates any potential solvent peaks that could interfere with or cloud the final analysis results. In addition, this method avoids the use of solvents, which can have negative environmental impacts, especially with popular cannabis solvents like butane, propane, or CO2, which can be hazardous or require high-pressure systems.

The Significance of Identifying Terpenes

Terpenes, a captivating array of compounds present in the cannabis plant, hold the key to its diverse aroma and flavor profile. These characteristics significantly affect consumer preferences, making terpenes an essential element in the cannabis market. Additionally, many isolated terpenes exhibit direct therapeutic properties, but their interactions with cannabinoids and other trace compounds must also be considered when employing cannabis for medicinal applications.

The “entourage effect” encapsulates the synergistic interplay among various cannabis compounds, including terpenes, which serves to enhance the plant’s medicinal properties. In a 2011 study published in the British Journal of Pharmacology, Dr. Ethan Russo chronicled several instances in which cannabinoid-terpene interactions produced complementary pharmacological activities, culminating in more robust therapeutic results than either pure cannabinoid or terpene extracts could achieve independently.

This observation holds significant implications for medical professionals prescribing cannabis and patients using it for medicinal purposes. Current practices for recommending medical cannabis strains frequently depend on trial and error or conjectures based on the CBD:THC ratio of the strain. However, patients may derive greater benefits from strains with a unique terpene profile that optimizes these synergistic interactions. Consequently, accurate and exhaustive terpene analysis methods are indispensable for studying these synergistic mechanisms and their effects with precision.

Numerous jurisdictions now mandate the inclusion of a terpene profile on the labeling or packaging of cannabis products sold within their boundaries. This requirement assists cannabis users in selecting a product that caters to their specific needs. For instance, in Connecticut, cannabis producers are obligated to provide a terpene profile and an inventory of all active ingredients constituting at least 1% of the cannabis batch on the label. In Maryland, even cannabinoids and terpenes present in amounts below 1 percent must be thoroughly disclosed on the packaging. Through the provision of verified terpene profiles on product packaging, cannabis users can make more informed choices.

Terpene Genomics: Revolutionizing the Cannabis Industry

In the world of cannabis, terpenes are responsible for the plant’s aroma, flavor, and even its effects on the body. For this reason, producers and cultivators strive to create strains that are most favorable for users, whether that means enhancing the plant’s scent and taste for recreational use or developing strains that cater to specific medical conditions. With the rise of the craft and medicinal breeding business in the cannabis industry, innovative approaches are essential to support this selective strain breeding.

One critical starting point for any breeding process is a full understanding of the genetic basis of cannabinoid and terpene oil profile variation. By using a vast amount of terpene profile data alongside modern genomic approaches, researchers can identify the sets of genes that promote the expression of individual terpenes. This information can help map genetic variants to oil profile variation and create a breeding roadmap that guides breeders towards specific terpene endpoints.

According to Dr. Keith Allen, Director of Bioinformatics at the prominent cannabis science and technology company, Steep Hill, there are at least 30 different terpene molecules commonly found in cannabis flowers. The combination of terpenes is a key factor in differentiating strains. Dr. Allen’s team focuses on the genetic study of terpenes in cannabis, working to enable targeted breeding and exploring the potential limits of these methods.

“As is the case with cannabinoids, there is a large family of genes responsible for making terpenes,” Dr. Allen explains. “By describing and mapping all of these genes, we can create tools for breeders who want to create strains with specific oil profiles, something that will become more and more important as we learn more about the effects of these molecules.”

Selective breeding of cannabis has been a common practice for thousands of years, resulting in infamous strains like “Afghani.” However, selectively breeding for terpene content is more complex than breeding for potency. A strain’s potency primarily relies on its THC content, while promoting a particular terpene profile involves manipulating dozens of different compounds within the strains. Nevertheless, by combining terpene analysis methods with modern genomic techniques, what was once thought impossible now seems achievable for the cannabis industry.