Terpenes are important because they contribute to the unique attributes of cannabis plants, both THC and CBD. Similar to how lavender is known for its distinct scent, terpenes are responsible for the plant’s aroma and flavor. They are known to possess specific medical properties that act synergistically with cannabinoids, enhancing each other's effects.
The interaction between cannabinoids and terpenes is known as the "entourage effect". The combined use of these two compounds have been shown to help aid a variety of ailments. For example, CBD in combination with the terpenes limonene, linalool, and pinene is used to treat acne. Adding caryophyllene, linalool, and myrcene to 1:1 CBD/THC extracts is used to treat sleeping disorders .
The importance of terpenes is discussed here, and it might lead to the question: how do we acquire the full benefits of terpenes and cannabinoids while avoiding degradation? In other words, when do they expire?
Terpenes are volatile and thermolabile (highly sensitive to heat). They easily decompose when exposed to oxygen, solvents, or light. This suggests that the distillation of cannabis oil (which requires a solvent) must destroy the terpene content. This means that any terpenes found in distillate products are synthetic. Unfortunately it is likely that solvents used to distill cannabis oil also contaminate the product.
Fortunately, supercritical fluid extraction has offered an effective means of separation of monoterpenes from sesquiterpenes and cannabinoids. However, it is very complicated and requires a strict protocol to be performed. Here is a detailed analysis of the temperature conditions required for supercritical carbon dioxide extraction:
“In order to develop terpene extraction condition utilizing supercritical carbon dioxide, it is essential to understand the relative solubility of terpenes in supercritical carbon dioxide. It was determined that monoterpenes have high solubility at 70 bar and 50°C while sesquiterpenes have low to mild solubility at these conditions. With the addition of a terpene specific collector (CS4), supercritical CO2 is an effective solvent for the extraction of terpenes from cannabis. The ability of supercritical carbon dioxide to return to a gaseous state once exposed to ambient conditions allows for simple terpene recovery and results in no detectable residual solvents. Monoterpene fractions were obtained from the terpene specific collector with high purity and no detectable cannabinoids. In order to recover highly volatile monoterpenes, CS4 needed to be chilled to -78°C. Plant waxes and cannabinoids co-elute with sesquiterpenes, which are collected from CS3. Due to the more robust nature of sesquiterpenes, these compounds can undergo post processing methods such as winterization with minimal to no degradation. The ability to separate monoterpenes from sesquiterpenes from cannabinoids allows for post processing of cannabinoids without the danger of terpene degradation“ .
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