diplomsko delo visokošolskega strokovnega študijskega programa I. stopnje
Tina Oprešnik (Author), Mojca Škerget (Mentor), Tina Perko (Co-mentor)

Abstract

Namen diplomskega dela je bilo preučiti in primerjati vsebnost celokupnih fenolnih spojin, antioksidativno aktivnost ter vsebnost celokupnih sladkorjev v devetih vzorcih. Analizirali smo štiri zeliščne likerje, tri sadne likerje in dva sirupa. Sadni likerji so bili borovničev, višnjev ter orehov liker. Kot sirupa smo preučevali melisin in bezgov sirup. Osem vzorcev je bilo izdelanih v domačih kuhinjah. Eden zeliščni liker – Jägermeister smo kupili v trgovini in nam je služil kot primerjava pri analizah med industrijsko proizvedenim in doma izdelanimi zeliščnimi likerji. Pri prvi analizi smo spektrofotometrično določili vsebnost celokupnih fenolnih spojin v vzorcih s Folin-Ciocalteu-ovo metodo. Nastalim barvnim kompleksom smo izmerili absorbanco pri valovni dolžini 760 nm. Ugotovili smo, da je bilo največ fenolnih spojin prisotnih v orehovem likerju (1,7116 mg fenolnih spojin na g vzorca), najmanj pa v domačem zeliščnem likerju (0,3740 mg fenolnih spojin na g vzorca). Antioksidativno aktivnost vzorcev smo preučevali spektrofotometrično z radikalsko metodo. Analiza je potekala z uporabo stabilnega 2,2-difenil-1-pikrilhidrazil (DPPH) prostega radikala pri valovni dolžini 515 nm. Iz rezultatov je razvidno, da je bil % inhibicije glede na referenčno raztopino največji pri orehovem likerju (79,5718 % inhibicija) in najmanjši pri melisinem sirupu (19,7164 % inhibicija). Najbolj razširjena kolorimetrična metoda, namenjena določanju vsebnosti celokupnih sladkorjev, je fenol-žveplova metoda. Nastalim oranžnim kompleksom vzorcev smo na UV-VIS spektrofotometru izmerili absorbanco pri valovni dolžini 490 nm. Največ sladkorjev je bilo v bezgovem sirupu (65,7235 g na 100 mL vzorca), medtem ko je bila najnižja vrednost pri kupljenem zeliščnem likerju (15,4612 g na 100 mL vzorca).

Keywords

celokupne fenolne spojine;antioksidativna aktivnost;celokupni sladkorji;UV-VIS spektrofotometer;zeliščni likerji;sirupi;diplomske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher: [T. Oprešnik]
UDC: 547.631.4:663.83(043.2)
COBISS: 20346646 Link will open in a new window
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Other data

Secondary language: English
Secondary title: THE CONTENT OF PHENOLIC COMPOUNDS IN FRUIT AND HERBAL BEVERAGES
Secondary abstract: The purpose of the thesis was to examine and compare the content of phenolic compounds, antioxidant activity and the content of total sugars in the nine samples. We analysed the four herbal liqueurs, three fruit liqueurs and two syrups. Fruit liqueurs were blueberry, cherry and walnut liqueur. Syrups were melissa syrup and elderberry syrup. Eight samples were made in a domestic kitchen. One herbal liqueur – Jägermeister we bought in the grocery store. This has served us as a comparison in analyses of industrially produced and homemade herbal liqueurs. By the first spectrophotometric analysis we examined the content of total phenolic compounds in samples with the Folin-Ciocalteu's method. The absorbance of the resulting coloured complexes were measured at a wavelength of 760 nm. We found that the majority of phenolic compounds were present in the walnut liqueur (1.7116 mg of phenolic compounds per gram of sample). The minimum value was in domestic herbal liqueur (0.3740 mg of phenolic compounds per gram of a sample). The antioxidant activity of samples was examined spectrophotometrically by the free radical method. The analysis was conducted with the use of a stable 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals at a wavelength of 515 nm. The results show that the % inhibition relative to the reference solution was the highest for walnut liqueur (79.5718 % inhibition) and the lowest for the melissa syrup (19.7164 % inhibition). The most widespread calorimetric method for the determination of total sugars is phenol-sulfuric method. The absorbance of the resulting orange complexes were measured at a wavelength of 490 nm. The total sugars were the highest in the elderberry syrup (65.7235 g per 100 mL of sample), while the lowest value was in the bought herbal liqueur (15.4612 g per 100 mL of sample).
Secondary keywords: phenolic compounds;antioxidant activity;total sugars;UV-VIS spectrophotometer;herbal liqueur;syrup;
URN: URN:SI:UM:
Type (COBISS): Bachelor thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages: IX, 37 str.
ID: 9161564