## 1 Introduction  
Hemp (_Cannabis sativa_ L.) is a herbaceous, wind-pollinated plant that is widespread around the world and belongs to the _Cannabaceae_ family. The species _Cannabis sativa_ L. (true hemp) includes fiber (_Cannabis sativa_ L. _var. sativa_) and Indian (narcotic) (_Cannabis sativa_ L. _var. indica_) hemp. These differ in their levels of cannabinoids, mainly THC, the content of which in fiber hemp is below 0.2% [1, 2, 3, 4]. Poland has a long tradition of growing cannabis. Hemp is cultivated in areas with valuable natural resources, including the Lublin region, Podlasie, and Greater Poland. The Lublin region currently ranks fourth in terms of its cultivation area, but it is first in terms of the number of farms. _C. saliva_ L. has recently received a lot of attention for its nutritional and pharmaceutical value, although in the past, it was grown mainly for the fibers from hemp stalk and for the oil from hemp seeds [5, 6, 7]. The medicinal use of cannabis has been known for over 5000 years, and the pharmacological properties of cannabinoids, dominant in cannabis, can be useful in the treatment of various diseases [7, 8]. Indeed, cannabinoids (phytocannabioids) are one of the most important bioactive compounds in cannabis [9]. The best-known cannabinoids found in _Cannabis sativa_ L. are THC and CBD. The panicle elements of the plant (inflorescences), along with the leaves, are used in the production of industrial hemp extracts. They contain volatile terpen and phytocannabinoids, including cannabidiol, better known by the trade name CBD. The latter is usually presented to consumers in the form of dietary supplements, cosme, and even drugs, although its production in Poland is currently prohibited. The popularity of cannabidiol is likely due to its pro-health and healing properties, some of which have been scientifically proven and some of which are described within the so-called natural medicine movement [10]. CBD oils, ointments, and capsules have a beneficial effect on general health and can be used in the symptomatic treatment of eczema and other skin diseases, as well as various types of pain, especially rheumatoid arthritis, joint diseases, cancer, and even multiple sclerosis. The health properties of CBD also factor into the popularity of daily skin care cosme that have been derived from it, the popularity of which increases every year. Hemp is also rich in natural antioxidants and other bioactive ingredients, such as bioactive peptides, phenolic compounds, tocopherols, carotenoids, and phytosterols. The content of these ingredients is mostly influenced by environmental and agronomic factors and, to a lesser extent, by genetic variability. Fibrous hemp inflorescences are a source of polyphenic compounds with proven health-promoting properties [11]. Bioactive substances are biologically active compounds of a natural origin that can have a beneficial and multidirectional effect on the body. As food ingredients, they can modify, strengthen, or weaken various body functions, thus limiting the development of disease processes. These compounds are characterized by antioxidant, anti-inflammatory, neuroprotective, antihypertensive, antiproliferative, and hypocholesterolemomic effects, which have mainly been assessed with in vitro studies [2,8,12,13,14,15]. In recent years, the demand for bioactive substances has increased, which has also resulted in a search for new, more efficient methods for their extraction. To this end, various separation techniques are used, such as supercritical fluid extraction, microwave-assisted extraction, accelerated solvent extraction, ultrasound-assisted extraction, and pulsed electric-field-assisted extraction. The ultrasound-assisted extraction method enables the extraction of bioactive ingredients in a very short time, at a low temperature, and with lower energy and solvent requirements [16].