Study of the Kinetics of Extraction Process for The Production of Hemp Inflorescences Extracts by Means of Conventional Maceration (CM) and Rapid Solid-Liquid Dynamic Extraction (RSLDE)

Abstract

In the present work, the kinetics of the extraction process from female inflorescences of Canapa sativa subsp. sativa var. sativa were studied, on the basis of determination of the content of cannabinoids: cannabidiolic acid (CBDA), Δ9-tetrahydrocannabinolic acid (THCA), cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC), before and after decarboxylation in the oven, in order to evaluate the possible use of the hemp extract obtained in the food sector. Therefore, both conventional maceration (CM) and rapid solid-liquid dynamic extraction (RSLDE), also known as cyclically pressurized extraction (CPE), were carried out, using parts of the plant approximately of the same size. The alcoholic extracts thus obtained were analyzed by high-performance liquid chromatography (HPLC) in order to calculate the percentages of cannabinoids present in the inflorescences and thus be able to evaluate the degree of decarboxylation. Furthermore, the extracts were dried to calculate the percentage of solid material present in it, that was made mainly by cannabinoids. The amount of substance extracted from the inflorescences was about 10% (w/w), for both cases considered. Therefore, the extraction yield was the same in the two cases examined and the final qualities were almost identical. However, the extraction times were significantly different. In fact, the maceration of hemp inflorescences in ethyl alcohol was completed in no less than 24 h, while with the RSLDE the extraction was completed in only 4 h. Finally, for a better understanding of the extraction process with cyclically pressurized extraction, a numerical simulation was carried out which allowed to better evaluate the influence of extractive parameters.

Comparative extraction of cannabinoids and terpenoids from Cannabis sativa L. using three solvents

“…When evaluating total yield by three sequential extractions, the effect of residence time within each solvent was much smaller. The extraction yield reaching a plateau after certain residence time was also reported by others (Gallo et al, 2020).…”

“…When evaluating total yield by three sequential extractions, the effect of residence time within each solvent was much smaller. The extraction yield reaching a plateau after certain residence time was also reported by others (Gallo et al, 2020). Figure 2d.e show the yield of terpenoids and cannabinoids relative to initial biomass by three sequential extractions (combined products) in response to extraction time.…”

Efficiency of Recovery of the Bioactive Principles of Plants by Comparison between Solid–Liquid Extraction in Mixture and Single-Vegetable Matrices via Maceration and RSLDE

“…The dynamic phase also allows for the rapid and complete mixing of the solid matrix and the instantaneous diffusion of the extracted substances throughout the mass of the liquid, avoiding supersaturation phenomena around the solid that could stop the extractive process. This system makes this technique effective both in terms of extraction time and recovery efficiency and the quality of extract of the active ingredients contained in the plant matrix, as demonstrated by its use in various fields of application, e.g., herbal, pharmaceutical, cosmetic and food [ 32 , 33 , 34 , 35 , 36 , 37 ].…”

Supercritical Carbon Dioxide Technology for Recovering Valuable Phytochemicals from Cannabis sativa L. and Valorization of Its Biomass for Food Applications

“…In addition, high-pressure technologies, such as pressurized liquid extraction (PLE) and SFE, also have been largely employed. PLE was used largely to obtain cannabinoids [47][48][49]; meanwhile, SFE is the most applied method to obtain oil [50][51][52][53][54], cannabinoids [55][56][57][58][59][60][61][62], volatile compounds [59,63,64], and phenolic compounds [46].…”