As the cannabis sector transforms from the underground to the legal market, product development and extraction processes have become a priority. To far, over 2,000 chemical compounds of the cannabis plant have been identified, each of which has a unique chemical property and requires a unique set of circumstances for preservation during drying and extraction. However, scholarly papers on these subjects concerning the cannabis plant are currently scarce.
This is a narrative review work that focuses on the drying and extraction procedures used to cultivate Cannabis sativa L. The PubMed, EMBASE, MEDLINE, Google Scholar, and Cochrane Library (Wiley) databases were searched for relevant keywords such as medicinal cannabis, extraction, solvent, cannabinoids, and terpenes.
93 papers were screened to identify relevant ones for this narrative evaluation. Twelve of them were rejected as being irrelevant. The studies that were excluded dealt with hemp seed oil or hemp fiber and protein. Solvent extraction is the most often used procedure for cannabis plants, according to this review. Although solventless and hydrodynamic extraction are well-known for their excellent yields and feasibility, additional research in these areas is necessary. In terms of drying, hang-drying is the most convenient approach; nevertheless, it may be phased out in the near future in favor of freeze-drying.
This analysis examines several drying and extraction techniques in order to assist in the selection of the most appropriate methods for various cannabis products and applications. This is accomplished by comparing classic and modern drying techniques, delving into the relevance of solvents in extraction, visiting solventless extraction technologies, and concluding with a comparison of conventional and alternative extraction methods.
In conclusion, based on current understanding, the most convenient way for medicinal cannabis extraction is through the use of organic solvents. However, additional research is required on several of the drying and extraction techniques. Additionally, future research should include establishing a green and sustainable technique of cannabis extraction.