## 5 Conclusions  
The results of the analyses of the packaging materials showed that the composition of the gases in the packages was created as a result of the strong respiration of the nettle leaves and the permeability properties of used materials which strongly influenced the preservation of the antioxidant compounds in packed nettle leaves. LDPE and BOPP were shown as the most suitable materials for the preservation of antioxidant compounds in nettle leaves. The highest content of total polyphenolics, with caffeoylmalic acid as the most dominant individual phenolic compound, as well as the highest antioxidant capacity, were observed in samples packed in LDPE, ensuring the preservation of even 88% of TPC and 96% of antioxidant capacity after 14 days of storage when compared to fresh unpacked material. High levels of photosynthetic pigments and polyphenolic compounds were also measured in leaves packed in BOPP. The biodegradable and most permeable material (PLA) did not retain the water content, while the least gas permeable packages (PA/PE) did not preserve the specific green color of nettle leaves. The results of the study show that properly chosen packaging materials with suitable permeability characteristics help to regulate the levels of O\({}_{2}\) and CO\({}_{2}\) inside the packaging, creating an optimal environment that slows down the respiration rate and potentially delays the nutritional and sensory quality loss of nettle leaves. This research has provided valuable data important for both the food industry and the scientific community that can serve as a basis for further research into the packaging of fresh nettle leaves. Further research could be directed towards the use of packaging in a modified atmosphere and the use of other sustainable materials combined with active and intelligent packaging, which would contribute even more to the preservation of antioxidant compounds in nettle leaves as well as to their freshness. Additionally, research can be focused on a market study to evaluate consumer demand for this product. It should be emphasized that proper packaging management can significantly reduce food waste, which is one of the key points of the European Green Deal.  
Conceptualization, M.D., J.S.Z., M.K., S.R., N.O. and Z.M.; methodology, M.D. and J.S.Z.; software, M.D., M.K. and P.P.; validation, M.D., M.K. and J.S.Z.; formal analysis, M.D., M.K. and P.P.; investigation, M.D., J.S.Z., M.K. and P.P.; resources, J.S.Z., M.K., S.R., N.O. and Z.M.; data curation, M.D.; writing--original draft preparation, M.D.; writing--review and editing, J.S.Z. and M.K.; visualization, M.D.; supervision, J.S.Z. and M.K.; project administration, S.V.; funding acquisition, S.V. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Croatian Science Foundation (Hrvatska zaklada za znanost www.hrzz.hr) under the project IP-2019-04-3325 URTICA-BioFuture-Nutritional and functional value of nettle (_Utria dioica_ L.) by application of modern hydroponic cultivation techniques.  
Not applicable.  
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.  
The authors declare no conflicts of interest.