20.500.12556/RUL-94354 Skupne fenolne spojine in antioksidativna učinkovitost ekstrakta kimchija Analysis of total phenolic compounds and antioxidant activity in kimchi extracts Kimchi je tradicionalna fermentirana jed, ki izvira iz Koreje. Namen diplomskega dela je bilo pripraviti domači kimchi in ga primerjatis kupljenim. Tako iz kupljenega kot domačega kimchija smo želeli pripraviti vzorce soka in ekstrakte odcejenega kimchija ter v njih določiti skupne fenolne spojine in antioksidativno učinkovitost (AOU). V raziskavi smo uporabili pakirani korejski kimchi baechu znamke Chongga in kimchi, ki smo ga pripravili sami, in sicer s sedemdnevno in tridnevno fermentacijo ter sveži nefermentirani kimchi. V pripravljenih vzorcih soka in ekstrakta kimchija smo pred opravljanjem analiz določili vrednost pH z uporabo pH lističev. Vsebnost skupnih fenolnih spojin smo v vzorcih domačega in kupljenega kimchija določili spektrofotometrično z uporabo Folin‒Ciocalteujevega reagenta in rezultate analize izrazili kot ekvivalent klorogenske kisline. AOU soka in ekstrakta kimchija smo določili z metodo lovljenja radikala DPPH• in rezultate analize podali kot ekvivalent troloksa. Najvišjo AOU smo določili v vzorcu domačega kimchija, ki smo ga pustili fermentirati tri dni (0,22 mg/g v soku in 0,38 mg/g v ekstraktu), in v vzorcu kupljenega kimchija (0,24 mg/g v vzorcu soka in 0,44 mg/g v ekstraktu). Ta dva vzorca sta se tudi najbolj približala v literaturi opisani optimalni vrednosti pH 4,2. Povprečna vrednost skupnih fenolnih spojin v vzorcih soka domačega kimchija znaša 0,27 mg/g, v ekstraktu pa 0,33 mg/g. V soku kupljenega kimchija je vsebnost 0,53 mg/g, v ekstraktu pa 0,42 mg/g. Iz opravljene raziskave lahko sklepamo, da čas fermentacije in vrednost pH, ki jo živilo doseže, vplivata na vsebnost fenolnih spojin in AOU. Kimchi is a traditional Korean fermented vegetable containing several ingredients. The purpose of this thesis was to compare homemade nonfermented fresh kimchi as well as kimchi fermented for seven and three days with store-bought kimchi by determining antioxidant activity (AOU) and the total phenolic content in kimchi juice and extracts. In our research, we used beachu kimchi by brand Chongga as well as kimchi made at home from locally bought ingredients. We measured the pH value of our samples with the use of pH paper. Total phenolic content of extracts was determined spectrophotometrically according to Folin‒Ciocalteu method, the results of the analysis were expressed as an equivalent of the chlorogenic acid. AOU was evaluated using DPPH• radical scavenging method. AOU was expressed as trolox equivalent. The highest AOU was determined in homemade kimchi that was left to ferment for three days (0,22 mg/g in juice and 0,38 mg/g in extract) as well as in the store-bought kimchi (0,24 mg/g in juice and 0,44 mg/g in extract). The pH values of these samples were close to the optimum pH value reported elsewhere (pH 4,2). The average total phenolic compounds in homemade kimchi juice was 0,27 mg/g and in in extracts 0,33 mg/g. The total phenolic compounds in store-bought kimchi juice was 0,53 mg/g and in extract 0,42 mg/g. From our research it can be concluded that fermentation duration and the pH value of kimchi affects the total phenolic content and antioxidant activity. fermentirana živila kimchi sok iz kimchija ekstrakt iz kimchija fenolne spojine antioksidanti antioksidativna učinkovitost analizne metode Folin‒Ciocalteu DPPH fermented foods kimchi kimchi juice kimchi extracts total phenolic compounds antioxidants antioxidant activity analytic methods Folin-Ciocalteu DPPH true false false [K. Hribar] Slovenski jezik Angleški jezik Diplomsko delo/naloga 2017-08-02 07:15:02 2017-08-02 07:15:08 2022-08-10 01:36:50 0000-00-00 00:00:00 2017 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 663/664:547.56:543.2 132134 4830584 757.pdf 757.pdf 1 EA36623461E442C010B6FC6B76108CBA 31945ed48111ca378a93442e0f6d22f519741b89ae6e4738df81fea6d8c44066 8203f2d2-a1b3-11eb-a523-00155dcfd717 20.500.12556/rul/70065e3d-22e1-4d82-99e4-72bcc46a113a https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=102559 Biotehniška fakulteta 0 0 0