magistrsko delo
Karmen Klemenc (Author), Helena Abramovič (Reviewer), Tanja Pajk Žontar (Mentor), Alenka Levart (Co-mentor)

Abstract

Ribje olje je bogato z večkrat nenasičenimi omega 3 (n-3) maščobnimi kislinami (MK), zaradi česar tovrstna olja in z njimi povezana prehranska dopolnila (PD) hitreje oksidirajo. Pri tem nastanejo primarni in sekundarni produkti oksidacije, zaradi česar so oksidirana olja prehransko manj kakovostna ali celo škodljiva. Cilj magistrskega dela je bil določiti vsebnost primarnih produktov, to je peroksidno število (PŠ) in sekundarnih produktov oksidacije, to je p-anizidinsko število (p-AŠ) in malondialdehida (MDA) ter vsebnost vitamina E v PD z n-3 MK. Analizirali smo 30 vzorcev, vsak vzorec je bil sestavljen iz dveh neodvisnih ponovitev. Dobljene rezultate smo primerjali s standardi kakovosti, podatki iz literature in z vrednostjo označeno na označbi. Izmed vseh analiziranih vzorcev jih je 73 % preseglo priporočeno zgornjo mejo za PŠ (5 meq O2/kg), razpon vrednosti pa je znašal od 1,3 do 26,1 meq O2/kg. Priporočeno zgornjo mejno vrednost za p-AŠ (≤20) je presegel 1 vzorec, razpon vrednosti pa je znašal od 20 do 51,8. Priporočeno zgornjo mejno totox vrednost (≤26) je preseglo 26 % vzorcev, razpon vrednosti pa je segal od 13,2 do 70,1. Pri tem določitev p-AŠ in totox vrednosti za vzorce iz krilovega olja ni bila mogoča. Noben vzorec ni vseboval take količine MDA, ki bi nakazovala na začetek izrazite oksidacije. Koncentracija prisotnega vitamina E se je med vzorci zelo razlikovala, saj se je njegova vsebnost gibala med 95 in 19682 mg/kg. Izmerjena vsebnost vitamina E v 4 vzorcih ni bila skladna z vsebnostjo označeno na označbi. Na podlagi rezultatov predpostavljamo, da vsebnost vitamina E ni imela vpliva na PŠ in totox vrednost, medtem ko so večje količine vitamina E izkazale večjo zaščito pred nastankom sekundarnih produktov oksidacije.

Keywords

prehranska dopolnila;maščobne kisline;omega 3;produkti oksidacije;vitamin E;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [K. Klemenc]
UDC: 613.292:577.115.3
COBISS: 163114243 Link will open in a new window
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Other data

Secondary language: English
Secondary title: Content of primary and secondary oxidation products and vitamin E in dietary supplements with omega 3 fatty acids
Secondary abstract: Fish oil is rich in polyunsaturated omega 3 fatty acids, which makes such oils and related dietary supplements very prone to oxidation. This creates primary and secondary oxidation products, which makes oxidized oils of lower nutritional quality or even harmful. The aim of the master's thesis was to determine the content of primary, i.e. peroxide value and secondary oxidation products, i.e. p-anisidine value and malondialdehyde as well as the content of vitamin E in dietary supplements with omega 3 fatty acids. A total of 30 samples were analyzed, each sample consisting of two independent repetitions. The obtained results were compared with quality standards, data from the literature and the values marked on the label. Out of all analyzed samples, 73 % exceeded the recommended limit for the peroxide value (5 meq O2/kg), and the value range was from 1,3 to 26,1 meq O2/kg. The recommended limit for p-anisidine value (≤ 20) was exceeded by one sample, and the range of values was from 20 to 51,8. The recommended totox limit (≤ 26) was exceeded by 26 % of the samples, with values ranging from 13,2 to 70,1. Determination of p-anisidine value and totox value was not possible for krill oil samples. None of the samples contained an amount of malondialdehyde that would indicate the onset of oxidation. The concentration of present vitamin E varied greatly among the samples, between 95 and 19682 mg/kg. The measured content of vitamin E in 4 samples was not compliant with the labelled value. Based on the results, we assume that the vitamin E content had no effect on the peroxide value and totox value, while higher amounts of vitamin E showed greater protection against the formation of secondary oxidation products.
Secondary keywords: food supplements;fatty acids;omega 3;oxidation products;vitamin E;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: 1 spletni vir (1 datoteka PDF (X, 45 str., [4] f. pril.))
ID: 19884034