20.500.12556/DKUM-71586 Ekstrakcija lubja kostanja s subkritično vodo Extraction of chestnut bark with subcritical water Biomasa predstavlja naravni vir vrednih komponent. Lubje kostanja vsebuje visoke vsebnosti taninov in različne fenolne spojine, ki se uporabljajo v medicini ter farmacevtski, kozmetični in prehrambeni industriji. Namen diplomskega dela je bil separirati vredne spojine iz lubja kostanja s subkritično vodo in optimizirati proces z uporabo metode odzivnih površin z zasnovo Box-Behnkenovega načrtovanja. Optimizirali smo tri ključne spremenljivke, in sicer temperaturo, čas in razmerje topilo/material, ter spremljali njihov vpliv na ekstrakcijski izkoristek in vsebnost vrednih komponent v lubju, kot so totalni fenoli, totalni tanini in antioksidativna aktivnost. V lubju smo dokazali prisotnost elagne in galne kisline, elagotaninov (veskalagin, kastalagin, 1-o-galoj kastalagin), sladkorjev (maltoza, glukoza, fruktoza in arabinoza) ter njihovih derivatov (5-HMF, furfural in levulinska kislina). Zadnji korak v diplomskem delu je bil določitev optimalnih pogojev, s katerimi bi dosegli najvišjo vsebnost elagne kisline ter zadovoljive vsebnosti totalnih fenolov in totalnih taninov. Biomass represents the natural source of valuable compounds. Chestnut bark contains high level of tannins and various phenolic compounds which can be utilized in medicine and pharmaceutical, cosmetic, and food industry. The aim of this work was optimization of subcritical water extraction process of chestnut bark using Box-Behnken response surface method. The influence of process parameters, such as temperature, extraction time and solid-solvent ratio, on extraction yield, yield of the main compounds, total phenol content, total tannin content and antioxidant activity was observed. The identified compounds were ellagic and gallic acid, ellagitannins (vescalagin, castalagin, 1-o-galloyl castalagin), sugars (maltose, glucose, fructose and arabinose) and sugar derivatives (5-HMF, furfural and levulinic acid). The final step of the work was determination of the optimal conditions of the process to obtain the bark extract highly rich in ellagic acid and with satisfactory level of total phenols and total tannins. subkritična voda navadni kostanj fenolne spojine tanini optimizacija procesa Box-Behnkenova metoda subcritical water sweet chestnut phenolic compounds tannins optimization of process Box-Behnken method true true false [A. Turk] Slovenski jezik Angleški jezik Diplomsko delo/naloga 2018-08-22 18:45:41 2018-09-10 13:47:14 2022-08-01 21:05:50 2019-07-11 18:47:39 2018 0 Maribor 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 547.98:582.747.2(043.2) 21950486 URN:SI:UM:DK:BAYXCXNO VS_Turk_Andreja_2018.pdf VS_Turk_Andreja_2018.pdf 1 90305F46D424477A282F283971736326 daa5aa1c7ce8fed1f5e7ac2e312ccc118cdde4bf131cbebe4beb0c0075a4d54e 45643b3b-7c10-11eb-bb7a-00155d0001ca 20.500.12556/dkum/fc88b2a4-bbc5-472a-b4f0-e7c7d1710c53 https://dk.um.si/Dokument.php?lang=slv&id=128881 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0