20.500.12556/RUL-174295 Vpliv izbranih kislin in antioksidantov na potek Maillardove reakcije v modelnih sistemih različnih monosaharidov ter asparagina Impact of selected acids and antioxidants on the Maillard reaction in monosaccharides-asparagine model system V magistrski nalogi smo preučili vpliv različnih dejavnikov na potek reakcij med reducirajočimi sladkorji ter prostimi aminokislinami med termično obremenitvijo. Osredotočili smo se na učinke dodatka izbranih kislin in antioksidantov ter na vlogo različnih reducirajočih sladkorjev in prostih aminokislin. Preučevali smo tudi vpliv prisotnosti fenilne in tiolne skupine ter molskega razmerja med aminokislino in sladkorjem. V eksperimentalnem delu smo uporabili tri analitske metode: termogravimetrično analizo (TGA), diferencialno dinamično kalorimetrijo (DSC) in FTIR-spektroskopijo, s katerimi smo spremljali spremembe mase med segrevanjem od 25 do 550 °C, toplotnega toka pri 110 °C ter absorbance v območju IR pri različnih časih segrevanja v sušilniku pri 110 °C. Rezultati so pokazali, da sta začetek in obseg reakcij odvisna od molskega razmerja glukoza:asparagin. Reakcije med aldozami in asparaginom potekajo v večjem obsegu ter se začnejo že po krajšem času termične obremenitve kot reakcije med ketozami in asparaginom. Primerjava cisteina in fenilalanina z alaninom je pokazala, da na potek reakcij vpliva tudi prisotnost tiolne in fenilne skupine. Dodatek kislin k vzorcu z glukozo in asparaginom v okolju nizke vodne aktivnosti vpliva na potek reakcij. Ugotovili smo tudi, da antioksidanti, kot sta askorbinska kislina (vitamin C) in Trolox (vodotopni analog vitamina E), prav tako vplivajo na potek reakcij med termično obremenitvijo. In the master’s thesis, we examined the influence of various factors on the reactions between reducing sugars and free amino acids during thermal treatment of the samples. We focused on the effects of adding selected acids and antioxidants, as well as the role of different reducing sugars and free amino acids. We also studied the influence of the presence of phenyl and thiol groups and the molar ratio between the amino acid and the sugar. In the experimental part, three analytical methods were applied: thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and FTIR spectroscopy, with which we monitored changes in mass during heating from 25 to 550 °C, heat flow at 110 °C, and IR absorbance at different heating times in a drying oven at 110 °C. The results showed that the onset and extent of the reactions depend on the glucose:asparagine molar ratio. Reactions between aldoses and asparagine proceed to a greater extent and start after a shorter period of thermal treatment compared to reactions between ketoses and asparagine. A comparison of cysteine and phenylalanine with alanine indicated that the presence of thiol and phenyl groups also affects the reactions. The addition of acids to the glucose–asparagine sample under low water activity conditions influences the course of the reactions. We also found that antioxidants, such as ascorbic acid (vitamin C) and Trolox (a water-soluble vitamin E analog), similarly affect the progression of reactions during thermal treatment. Maillardova reakcija monosaharidi aminokisline asparagin askorbinska kislina kisline antioksidanti diferenčna dinamična kalorimetrija termična gravimetrija FTIR spektroskopija Maillard reaction monosaccharides amino acids asparagine ascorbic acid acids antioxidants differential scanning calorimetry thermogravimetry FTIR spectroscopy true false false [J. Hriberšek] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2025-10-01 07:16:17 2025-10-01 07:16:22 2025-11-20 03:37:15 0000-00-00 00:00:00 2025 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 577.1:664:544.016.2 267090 251660035 54102.pdf 54102.pdf 1 2125F258111AC9A2377FCE03C6A67B0A 2b723cd69742a457dce5bfa460186e9bc06490515e2dfacd50f414c60e8f733b 908b5d8f-9e85-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=219083 Biotehniška fakulteta 0 0 0