20.500.12556/RUL-178449 Antioksidativno delovanje sort soje (Glycine max. (L.) Merrill.) Antioxidant activity of soybean (Glycine Max (L.) Merrill) cultivars V magistrskem delu smo raziskali antioksidativno (AOX) delovanje izvlečkov soje (Glycine max (L.) Merrill) s poudarkom na vplivu ekstrakcijskih metod in genotipskih razlik. AOX aktivnost smo ovrednotili s spektrofotometričnim DPPH• testom (kinetika reakcije), TLC-DPPH• metodo s semi-kvantitativno oceno (CI-AA indeks) ter HPLC-DAD-MSⁿ za identifikacijo in kvantifikacijo fenolnih spojin. Statistične analize (ANOVA, Kruskal-Wallis, regresija) so omogočile primerjavo med 16 ekstrakcijskimi metodami in 10 sortami soje. Rezultati so pokazali, da polarnejša topila omogočajo večji izplen fenolov, a ne nujno večjo AOX aktivnosti. Sukcesivne ekstrakcije so potrdile, da odstranitev lipofilnih komponent delno prispeva k izboljšani AOX aktivnosti. Soxhletova ekstrakcija je dosegla najboljše rezultate v polarnih in nepolarnih sistemih, vendar je spremenila kemični profil izvlečkov. Izvlečki, pridobljeni z agitacijo na magnetnem mešalu, so razkrili, da lipofilni AOX (tokoferoli, karotenoidi) in amfifilne molekule pri metodah s polarnimi topili ostanejo podcenjeni. Sorte so pokazale manjše razlike; izstopala je sorta 'Smuglyanka', ki je bila po kinetiki reakcije primerljiva z α-tokoferolom (0,1 mM), po učinkovitosti inhibicije DPPH• pa s troloksom (0,1 mM). Korelacijska analiza je pokazala najmočnejšo povezavo med AOX aktivnostjo in glikozidi (r² = 0,88), zmerno pri skupnih fenolih (r² = 0,59), pri metodah ekstrakcije pa podobno za fenole in glikozide (r² ≈ 0,64) ter šibko pri aglikonih (r² = 0,28). Ugotovitve kažejo, da so glikozidi ključni nosilci AOX aktivnosti v polarnem analitskem okolju in da izbira ekstrakcijske metode ter genotipa odločilno vpliva na AOX delovanje izvlečkov soje. In this Master’s thesis, we investigated the antioxidant (AOX) activity of soybean (Glycine max (L.) Merrill) extracts, with emphasis on the influence of extraction methods and genotypic differences. AOX activity was assessed using the spectrophotometric DPPH• assay (reaction kinetics), the TLC-DPPH• method with semi-quantitative evaluation (CI-AA index), and HPLC-DAD-MSⁿ for the identification and quantification of phenolic compounds. Statistical analyses (ANOVA, Kruskal-Wallis, regression) enabled comparisons between 16 extraction methods and 10 soybean varieties. The results showed that more polar solvents allowed for a higher yield of phenolic compounds but not necessarily higher AOX activity. Successive extractions confirmed that the removal of lipophilic compounds partly enhances AOX activity. Soxhlet extraction achieved the best results in both polar and nonpolar systems but altered the chemical profile of the extracts. Extracts obtained by magnetic stirring revealed that lipophilic AOX (tocopherols, carotenoids) and amphiphilic molecules remain underestimated in methods with polar solvents. The varieties showed moderate differences; 'Smuglyanka' stood out, being kinetically comparable to α-tocopherol (0.1 mM) and, in terms of DPPH• inhibition efficiency, to Trolox (0.1 mM). Correlation analysis showed the strongest relationship between AOX activity and glycosides (r² = 0.88), a moderate one with total phenolics (r² = 0.59), and for extraction methods, similar correlations for phenolics and glycosides (r² ≈ 0.64) but weak for aglycones (r² = 0.28). The findings indicate that glycosides are the key carriers of AOX activity in polar analytical environments and that the choice of extraction method and genotype critically determines AOX activity of soybean extracts. soja sorta ekstrakcija izoflavoni antioksidativno delovanje reakcijska kinetika soybean varieties extraction isoflavones antioxidant activity reaction kinetics true false false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2026-01-28 07:15:52 2026-01-28 07:15:58 2026-01-29 04:45:43 0000-00-00 00:00:00 2026 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 278696 266445827 56216.pdf 56216.pdf 1 6D8920034F61DD6D2F640B87A42AAF24 14f922cac9f7fff7a91657fc1bc67d673fac56f41daed1d74b7af7ed1c6e9e09 ca57069f-fc10-11f0-a1ba-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=226334 Biotehniška fakulteta 0 0 0