## 2 Issue Contents
The study showed that the recovery of these plant residues could be an essential source of biologically active compounds. In this way, the impact of the accumulation of plant waste on the environment is minimal. In [7], the use of by-products from yellow onion skins (_Allium cepa_ L.) was detailed, mainly by capitalizing on the flavonoid component. Extraction in hot water at 70 \({}^{\circ}\)C was performed, and the resulting extract was freeze-dried. Several formulas were extracted before being dried, and an in vitro digestion study demonstrated stability in gastric transit and a controlled release of flavonoid bioactive components during the intestinal phase. The study also showed thermal stability and a controlled pH, indicating that they can be used as functional food ingredients. In [8], the use of a functional product to inhibit the proliferation of uropathogenic strains of _Escherichia coli_ was reported. The product consisted of an ethanolic extract of cranberry fruit (_Vaccinium vitis idea_ L.), St. John's wort aerial parts (_Hypericum perforatum_), thymme aerial parts (_Thymus vulgaris_ L.), propolisics tincture with 27% dry mass, thymse essential oil, and rosemary essential oil. The tests were performed in a new in vitro bladder simulation system. The in vitro study showed the crucial inhibitory capacity of the proposed product. This initial in vitro study intended to investigate recurrent infections. New functional products were also tested, considering the inhibition of biofilm formation, which was an innovative in vitro research perspective. The system allowed various uropathogenic strains, which are associated with the use of a urinary catheter and participate in the formation of biofilm and the proliferation of inflammatory processes, to be tested. In [9], the effect of gamma radiation on the mycelium of the fungus _Fomes fomentarius_ was presented. A \({}^{60}\)Co source was used to induce oxidative stress. The impact on antioxidant stability and total phenol content was determined after 24 h. It was found that 300 Gy was the optimal dose for the extracts in the functional products industry. In [10], a process for use in the submerged cultivation of the mycelium of the fungus _Inonotus obliquus_ was presented to optimize the culture medium to obtain biomass. By analyzing six environmental components and pH, batch bioreactor cultures were performed to confirm the data that was gained from mathematical modeling. This optimized medium had a composition that contained (g/L): malt extract 2.15299, yeast extract 3.99296, fructose 11.0041, soluble starch 17.4, MgSO\({}_{4}\) 0.1 g, and CaCl\({}_{2}\) 0.05. In [11], chromatographic and NMR methods described the chemical composition of extracts from callus, cell suspension, and _Rhaponticum extramoides_ roots. Flavonoids, such as ecdysteroids and anthocyanins, can inhibit the proliferation of tumor cells and have other biological effects, which can be used in the future to produce biopharmaceuticals. In [12], the authors addressed a current health problem: recurrent urinary tract infections and the increasing presence of antibiotic-resistant strains. The paper considered the effect that some less-used plant species have on managing recurrent urinary tract infections. These were pomegranate (_Punica granatum_ L.), chokeberry (_Aronia melanocarpa_ Michx. ), and comenian cherry (_Cornus mas_ L.), and evidence of their potential in the prevention of these infections or as an adjunct to antibiotic therapy was provided. In [13], the effect of heat treatment on bioactive compounds contained in microalgae was presented as an alternative to increasing the consumption of functional foods. The study showed that there was an increase in oxidative processes, even in the case of short heat treatment times. Phenolic compounds are among the most affected molecules. The effect on the pigments causes discoloration, and the amount of iodine is significantly reduced.