## 1 Introduction  
The most often methods used for extracting biologically active compounds include Soxhelt extraction, maceration, carbon dioxide extraction, microwave-assisted extraction (MAE), pulsed electric field assisted extraction and pressurized solvent extraction [1; 2; 3]. Currently, techniques belonging to the so-called green chemistry, where electricity is saved and the consumption of solvents is reduced due to environmental protection are getting more and more popular [4; 5; 6]. One of them is ultrasound-assisted extraction (UAE) which uses ultrasonic vibrations and solvents to extract desirable substances from various plant matrices [7]. The ultrasonic field is applied, among others, to support the extraction of active substances, e.g., flavonoids, anthocyanins, carotenoids, flavonoids, polysaccharides, but also many other substances from plant matrices-both from whole plants and by-products [8; 9; 10; 11; 12]. For example, ultrasound is used to extract pectins from pomeranate peel [13] and jack-fruit peel [14], polysaccharides from rambutan peel [15], pectin from graprefruit peel [16], polyphenols from pomeranate peel [17], antioxidants from baobab seeds [18], a bioactivecompound from mulberry leaves [19], phenolic components and anthocyanins from grape seeds [20], biophenol from olive leaves [10] and carotenoids from tomato waste [21]. The extraction is carried out using an ultrasonic probe system or an ultrasonic bath. Due to the way the ultrasonic processor works, it can be distinguished between the continuous and pulsed modes [22; 23; 24; 25]. Significant parameters determining the efficiency of ultrasound-assisted extraction are ultrasound intensity, frequency and operating mode of the ultrasonic generator. The duty cycle associated with the mode of operation is the ratio of the duration of the ultrasonic pulse to the total ultrasonic treatment time. The pulse duration is the time the ultrasonic transducer remains \"on\" while the pulse interval refers to the time that the ultrasonic transducer remains \"off\". The sum of the pulse duration and the pulse interval is called cycle time. A pulsed ultrasound field is used to obtain various bioactive compounds. Most often, literature reports concern the use of pulsed ultrasound-assisted extraction (PUAE) for the evaluation of the efficiency, activity and kinetics of antioxidant extraction from the dry peel of pomegranate [26], the yield of flavonoids, vitamin C and antioxidant activity of papaya pulp and peel extracts [27], efficiency of protein extraction from bitter melon seeds [28], efficiency of extraction of polyphenols from olive pomace [29], the extraction efficiency of phenolic compounds from carob pulp [30] and the extraction efficiency of the camptothecin from Nothapdytes nimmoniana plant [31]. Research by [PERSON] et al. showed that the extraction assisted with the pulsed ultrasonic field saves about 50% of electricity compared to the use of the continuous field [26]. Similar conclusions from the research were obtained by [PERSON] [30], indicating a slightly higher efficiency with the use of ultrasound in the pulsed mode. Studies by [PERSON] [32] show lower energy consumption in the pulsed mode (80 kJ) compared to the 190 kJ in continuous mode while maintaining a similar extraction efficiency. The effect of the ultrasonic field parameters on the power output in the process of extracting bioactive ingredients is not described in large numbers in the literature. [PERSON] et al. [33] assessed specific energy consumption in the extraction of bioactive compounds from hawthorn berries. The authors observed significantly higher specific energy consumption during the use of the continuous mode than the pulsed ultrasound mode. Pulsed ultrasound-assisted extraction reduced energy consumption from 20% to 51% while providing a higher process efficiency than continuous ultrasound-assisted extraction.