## 3 Results and Discussion
### Sustainable Production of Sea Buckthorn Fruit Pomace  
Sustainable production of sea buckthorn pomace is a key element in minimizing industrial waste and promoting a circular economy. The use of sea buckthorn pomace as a secondary raw material not only allows one to reduce waste but also promotes the production of functional food with high nutritional value [19]. Thanks to modern pressing/squeezing and processing technologies, sea buckthorn pomace can be successfully incorporated into various food products, contributing to effective resource management and environmental protection [1].  
The use of enzyme preparations for the maceration of fruit and vegetable pulp is used to facilitate the pressing process, which in turn contributes to increased juice yield. Preparations used for pulp maceration are composed of pectinolytic enzymes, hemicellulases, and cellulases. The action of hemicellulose enzymes, in addition to supporting the pressing process, prevents the occurrence of secondary turbidity in the juice that is caused by an excessive amount of soluble hemicellulose. An appropriately selected (for specific raw materials) enzyme preparation also facilitates further juice processing, i.e., depectimization, clarification, and filtration of the juice [39].  
Sea buckthorn fruit fiber is obtained as a by-product during oleosome production [40]. In technology, for economic reasons and due to the fact that preparations significantly affect the structure of the fiber and the bioavailability of the proteins, such as oleosome, that are the main components of the final product, enzymatic maceration is not used. The pomace constituting the by-product was dried at 50 \({}^{\circ}\)C, separated to remove seeds, and then crushed.  
Processing sea buckthorn fruit pomace without the use of enzymes, although more technologically demanding, can be equally valuable due to the preservation of the fiber structure and the bioavailability of nutrients. Such a process also allows one to obtain a raw material in line with consumer trends toward a preference for natural and less processed products [41]. Therefore, the sustainable production of sea buckthorn pomace can be particularly valuable, supporting the development of an environmentally friendly industry [1; 3] that is in line with consumer expectations.  
The balance of the efficiency of sea buckthorn pomace production is a key element of sustainable processing, allowing one to assess the efficiency of raw material use and minimize waste. In the process of the enzymatic maceration of fruit pulp, juice yield is increased, and the volume of remaining pomace is reduced, which contributes to better resource management [19; 42]. In addition, the optimization of the drying and separation of seeds allows one to obtain a stable raw material for the production of functional food products without harming the environment [1]. Such a balance is also necessary to achieve economic and ecological efficiency in production, thus supporting the circular economy [3; 41].  
Experimental research, which may be the basis for creating the technology for processing sea buckthorn fruit on an industrial scale, has shown that, as a result of pureeing 1000 kg of fruit, approximately 200 kg (with the use of an enzymatic preparation) and approximately 300 kg (without the enzymatic preparation) of wet pomace are obtained. The pomace, for further extraction, was subjected to pressing using a hydraulic press (Figure 5).  
As a result of such a procedure, the following mass division was obtained: secondary juice constituting about 60% and pomace about 40% in the case of enzymatic processing and 51% secondary juice and 49% pomace in the variant without the enzyme preparation. In the subsequent procedure, the secondary juice was combined with the primary juice and the pomace, dried at 50 \({}^{\circ}\)C, could potentially be an intermediate product for the production of a bioactive caroten-fiber concentrate (fiber) or a carotenoid-phospholipid extract.