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Identifier 000416860
Title Συγκριτική μελέτη των πραγματικών έναντι των αναφερόμενων τιμών Ω-3 λιπαρών σε διατροφικά συμπληρώματα στην Ελλάδα και εκτίμηση του ρυθμού αυτοοξείδωσής τους σε ελεγχόμενες συνθήκες
Alternative Title A comparative study between actual and state value Omega-3 dietary supplements in the Greek market and assessment of the autoxidation rate in controlled conditions
Author Σαλιαΐ, Νικολία Α.
Thesis advisor Ρίζος, Απόστολος
Reviewer Τσατσάκης, Αριστείδης
Τζατζαράκης, Εμμανουήλ
Abstract Ω-3 are essential fatty acids that humans and other animals need to ingest because the body requires them for good health but can not synthesize them. They are essential components of human diet, which are in particularly high proportions in fish oils. Consumption of ω-3 fatty acids has been shown to have beneficial effects because they have antioxidant and anti-inflammatory properties. In the market, these fatty acids exist as dietary supplements that are very widespread. The aim of the present study is to compare the actual and state value of the reported ω-3 dietary supplements, and assessment of the autoxidation rate in controlled conditions. Ten (10) different samples of dietary supplements that are available in the Greek market were analyzed. Firstly, using gas chromatography - mass spectrometry (GC-MS) was quantitative analysis of fatty acids and classifying these in saturated, monounsaturated, polyunsaturated fatty acids (SFA / MUFA / PUFA). Subsequently, the concentration of EPA and DHA was quantitated and a comparison of the actual values determined against the reported values. The deviation of the EPA is 43.6% less than the reported value to 165.3% more. While DHA from 21.5% less to 153.9% relative to the indicated value on the sample label. From 10 samples only 2 containing a higher concentration than the indicated value in both EPA and DHA. A sample only contains larger amount in DHA than that on the label, while in contrast it contains a smaller quantity in EPA. The remaining 7 samples contain less than that reported in both EPA and DHA. Next, the rate of autoxidation of dietary supplements is determined, 8 of the 10 samples was analyzed, because 2 of these samples was not possible to analyze due to the structure of the capsule containing fish oil. The degree of oxidation measuring by the peroxide value (PV) and the anisidine value (AV), and the total oxidation value (Totox). As for peroxide value (PV), half of the samples were above the allowable limit, while for anisidine value (AV) only one sample was above the allowable limit and according to the total number of oxidation (TOTOX) three of the eight samples were above the allowable limit. Finally, the rate of autoxidation was evaluated under controlled conditions, in particular in the samples tested for external effects, they placed in a bright place at 20 - 25oC for 28 days, no significant variation in oxidation was observed. However, when the effect of temperature was measured at 37 oC and 47oC for 28 days, the samples were not significantly oxidized at 37oC for 28 days, whereas on 47oC the samples were oxidized too rapidly resulting in 20 days be completely destroyed, in particular capsules melted and became a single mass.
Language Greek
Subject DHA
EPA
GC-MS
Διφωσφονικοί υποκαταστάτες
Εικοσαπενταενοϊκό οξύ
Εικοσιδυαεξαενοϊκό οξύ
Ιχθυέλαιο
Πολυακόρεστα
Issue date 2018-07-18
Collection   Faculty/Department--Faculty of Sciences and Engineering--Department of Chemistry--Post-graduate theses
  Type of Work--Post-graduate theses
Permanent Link https://elocus.lib.uoc.gr//dlib/7/5/8/metadata-dlib-1530599497-976586-11817.tkl Bookmark and Share
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