diplomsko delo
Blaž Toplak (Author), Mitja Kolar (Mentor)

Abstract

Kontrola kakovosti olj in maščob se dnevno izvaja v prehrambeni kemiji in industriji. Vsebnost antioksidantov v rastlinskih oljih je zelo pomembna pri določanju stabilnosti izdelkov. Vitamin E sodi v eno največjih skupin naravnih antioksidantov, ki vključuje več tokoferolov in tokotrienolov. Za te naravne fenolne spojine je značilno, da so elektrokemijsko aktivne. V diplomski nalogi sem določal vitamin E z uporabo elektrokemijske tehnike - diferenčne pulzne voltametrije (DPV) v sončničnem, ekstra deviškem oljčnem in konopljinem olju. Metodo sem najprej optimiral z določanjem najustreznejših reakcijskih pogojev. Po določitvi optimalnih pogojev sem vitamin E iz vzorcev rastlinskih olj ekstrahiral z dvema različnima postopkoma - prvi je bil postopek direktne ekstrakcije vitamina E v absolutni etanol, drugi pa je vseboval saponifikacijo olja in nadaljnjo ekstrakcijo. Za določanje sem uporabil metodo direktne ekstrakcije, ker se je izkazala za ustreznejšo in dobro ponovljivo. Slednjega pri metodi s saponifikacijo nisem dosegel. Določanje vitamina E v rastlinskih oljih z diferenčno pulzno voltametrijo na elektrodi iz steklastega ogljika(GCE) se je izkazalo za dobro in učinkovito pri oljih z višjo koncentracijo α-tokoferola.

Keywords

analizne metode;elektrokemija;elektrokemijske metode;diferenčna pulzna voltametrija;voltametrični sistem;elektrode;vitamin E;ekstrakcija vitamina E;metode določanja vitamina E;diplomske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [B. Toplak]
UDC: 543.552:577.161.3(043.2)
COBISS: 13931011 Link will open in a new window
Views: 457
Downloads: 136
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Other data

Secondary language: English
Secondary title: Determination of Vitamin E in vegetable oils using differential pulse voltammetry
Secondary abstract: Quality control of oils and fats is important in food chemistry and in the food industry. The content of antioxidant substances in vegetable oil products is of great importance for determining the stability of the products. Vitamin E represents one of the largest groups of natural antioxidants, including several tocopherols and tocotrienol compounds. These phenolic compounds are among the many naturally occurring substances known to be electrochemically active. In my work, I have determined vitamin E using differential pulse voltammetry (DPV). I have specified vitamin E in sunflower oil, extra virgin olive oil and hemp oil. First I optimized the method by determining optimal conditions. Then I tried to extract vitamin E from vegetable oil samples using two different techniques. The first was the method of direct extraction of vitamin E in absolute ethanol and the second involved saponification of the oil and further extraction. For the determination of vitamin E, I used the method of direct extraction because it was repeatable. I did not achieve this with the saponification method. The determination of vitamin E by differential pulse voltammetry has proven to be an effective method in oils with a higher concentration of α- tocopherol.
Secondary keywords: electrochemistry;differential pulse voltammetry;vitamin E;
Type (COBISS): Bachelor thesis/paper
Study programme: 1000374
Thesis comment: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, VSŠ Kemijska tehnologija
Pages: 43 f.
ID: 11628101