Optimization of Trimming Techniques for Enhancing Cannabinoid and Terpene Content in Medical Cannabis Inflorescences

Cannabis sativa L. inflorescences are widely used in the medicinal field as treatments for a variety of symptoms and illnesses due to their unique phytochemicals such as cannabinoids and terpenes. Common postharvest procedures for cannabis inflorescence include trimming, followed by drying, curing, and subsequent storage. The postharvest trimming step, particularly its timing (pre- or post-drying) and the extent of trimming, is not optimally refined in terms of its impact on the cannabinoid and terpene content. In this study, our objective was to identify the optimal trimming conditions for a commercially available medicinal cannabis hybrid chemovar, with the goal of maximizing its cannabinoid and terpene content.

To achieve this, we investigated the effects of pre- versus post-drying trimming and evaluated the impact of mild versus aggressive trimming prior to drying on the cannabinoid and terpene profiles using liquid and gas chromatography.

Our results indicated that pre-drying mild trimming yielded the highest cannabinoid concentration, possibly due to optimal balance between stress signals and precursor influx from the sugar leaves to the inflorescence. On the other, post-drying trimming yielded the highest terpene content.

Identifying the optimal trimming conditions that maximize both cannabinoid and terpene levels in cannabis is challenging. Therefore, growers face a decision in their trimming practices: to prioritize either enhanced cannabinoid content or increased aromatic terpene concentrations, as optimizing for both simultaneously appears to be difficult.