Hemp (Cannabis sativa L.) has been known as a source of fibres, oil and medicines since ancient times (4000 B.C.). The most known cannabinoids responsible for pharmacological properties are psychoactive Δ9-tetrahydrocannabinol (THC) and non-psychoactive cannabinoids such as cannabidiol (CBD), cannabigerol (CBG), cannabichromene (CBC) or cannabinol (CBN). Fast and increasing interest in using low-THC (<0.2%) hemp requires the development of efficient methods for extracting bioactive substances. The right choice of extraction method is important for obtaining valuable cannabinoids. The aim of the work was comparison of the conventional solid-liquid extraction method using dynamic maceration (DM) and ultrasound assisted extraction (UAE). For extraction with ethanol (40%, 60% and 80%) were selected fresh panicles of monoecious variety Beniko (2.55% CBD and 0.06% THC) allowed to cultivation in Europe. After harvesting, the panicles were frozen in liquid nitrogen and stored in a freezer (-20°C). For 40%, 60% and 80% ethanol extraction, dynamic maceration was used during which the plant material was shaken in the dark (100 rpm, 72h) and ultrasound assisted extraction (45 Hz, 0.5 h). The conducted research showed the highest content of CBD (361.3 µg/ml) during extraction with 80% ethanol combined with ultrasound. On the other hand, dynamic extraction with 60% ethanol allowed to obtain 352.7 µg/ml of CBD. The obtained results indicate that the most efficient method of extraction is ultrasound assisted extraction, however, dynamic maceration with shaking may be an alternative method.
The research was funded by Polish Ministry of Agriculture and Rural Development, resolution of the Council of Ministers no: 171/2017.
