Vapor Phase Terpenes Mitigate Oxidative Degradation of Cannabis sativa Inflorescence Cannabinoid Content in an Accelerated Stability Study

Introduction: As Cannabis sativa L. (Cannabaceae) ages, inflorescence phytochemicals are susceptible to oxidative degradation. Reduction of Δ⁹-tetrahydrocannabinol (Δ⁹-THC) content has the potential to impact the reliability and accuracy of dosing. Advances that improve cannabinoid stability during storage would have an important impact in medical cannabis markets. Reported here is the use of C. sativa terpenes with antioxidant properties that improve inflorescence cannabinoid stability.

Materials and Methods: Killer Kush inflorescence samples were stored in a temperature-controlled environment, in opaque jars. To accelerate the rate of oxidate degradation, samples were stored with the oxidizing agent hydrogen peroxide. Vapor phase terpenes were added to inflorescence packaging. Two terpene blends and three different dosage amounts were evaluated. Inflorescence stability samples were prepared in triplicate for each sample type. Cannabinoid content was quantitatively assessed after 24, 81, and 127 days of storage using high-performance liquid chromatography. Terpene content was assessed using headspace gas chromatography mass spectrometry. Results from inflorescence stored with and without external terpenes were compared by analysis of variance (ANOVA) data processing.

Results: After 127 days of storage, inflorescence in the accelerated study experienced a loss of 18.0% and 34.3% total Δ⁹-THC content for samples stored with and without external terpenes, respectively. The differences in cannabinoid content were found to be statistically significant at all timepoints using ANOVA processing. In the nonaccelerated study, only one of the six sample types investigated had a statistically significant greater total Δ⁹-THC content than control at all timepoints. Nevertheless, a dose-dependent relationship between the amount of external terpenes added to inflorescence and the preservation of total Δ⁹-THC content was observed.

Discussion: In the accelerated study, exogenous terpenes reduced the degradation of inflorescence cannabinoid content by 47.4%. This represents the first reported addition of terpene antioxidants to inflorescence packaging for cannabinoid preservation. Of note, the antioxidants used in this system can be obtained from C. sativa. This is advantageous from a toxicological perspective as inhaling synthetic antioxidants presents unknown and unpredictable risks. When fully developed, the novel system has applications for inflorescence packaged for individual sale, as well as long-term storage of bulk biomass.