Cannabinoids Enriched Extracts from Industrial Hemp Residues

Abstract

Obtaining phytocannabinoids, associated with various medicinal and therapeutic properties with no reported side effects, is one of the hot topics. The phychotropic Δ 9 -tetrahydrocannabinol (THC) is less than 0.2 % in industrial cultivars therefore can be grown legally in many EU countries. Harvesting and processing of hemp for fiber or seeds generates large amount of wastes containing substantial amounts of bioactives such as cannabidiol (CBD) which are the primary cannabinoids along with cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), and cannabichromene (CBC).The aim of this work was to optimize the extraction of cannabinoids from industrial hemp threshing residue using supercritical carbon dioxide extraction in pilot scales. The effects of extraction pressure and temperature on the extraction yield were evaluated. Three ground and pelleted samples of the same type but with different harvesting time were also compared. After derivatization of the samples the cannabinoids and the minor THCs were quantified by GC-MS. The extraction yields were between 0.2 -6.59 g/100 g dry mass depending on the source of hemp residue and on the process parameters of the extraction process. By increasing the pressure of extraction (in the range of 25-45 MPa at 45 °C) the extraction yields increased, meanwhile the yields of cannabinoids showed no significant increase. The volatile compounds were successfully separated from the cannabinoids with fractionated separation. From hemp threshing residues essential oil free extracts with high content of cannabinoids were obtained at 35 MPa extraction pressure and 45 °C temperature setting the first separator at 8 MPa and 40 °C.

Extraction of Phenolic Compounds and Terpenes from Cannabis sativa L. By-Products: From Conventional to Intensified Processes

“…Both works concluded in a better EO yield in the SFE extract than in the HD extract. The use of SC-CO 2 has great advantages in comparison to HD, such as the absence of damaged compounds with the use of low temperature, the direct recovery of the EO and the possible fractionation, similar to those done in the works of Da Porto et al (2014) [104] and Vági et al (2019) [105], with the isolation of volatile compounds from other extracted components. Moreover, according to [104] SC-CO 2 extraction would exhibit lower energy consumption compared to hydrodistillation (4.5 kWh/kg compared to 9.6 kWh/kg).…”

“…Up to 1.5 g/100 g DW of volatile compounds have also been recovered from cannabis in a separate fraction from cannabinoids. This time, the extract is fractioned in a first separator retrieving the cannabinoids fraction while a second one recovers the terpene fraction [105].…”

Cannabinoids—Characteristics and Potential for Use in Food Production

“…Knezevic et al [157] measured residual cannabinoid (CBDA, CBD, ∆9-THCA, ∆9-THC, and CBN) in teas prepared from fibrous hemp. The samples were prepared at different temperatures (43,55,70,85, and 97 • C), volumes (59,100,150,200, and 241 mL), and times (6, 10, 15, 20, and 24 min). The initial CBDA content in the plant material was 4073 mg/kg.…”

Preface

“…Innovative applications are presented for plane tree bark [11], hawthorn berries [12], and hemp threshing residues. [13] It is our hope that the Readers will find the papers interesting and useful. The next conference is to be held in Budapest, in 2021; for the announcement please consult later the website sfe.kkft.bme.hu, where the abstract book and contact information of all presenters will be available as well.…”