Karakterizacija kvaliteta, nutritivne vrednosti i stabilnosti devičanskih maslinovih ulja proizvedenih u različitim regionima Libije

Abstract

U ovoj tezi, uz pomoć literaturnih podataka prezentovano je geografsko poreklo masline i maslinovog ulja, njegova upotreba tokom istorije, proizvodni proces, senzorska svojstva, nutritivna vrednost i sastav masnih kiselina i održivost. U eksperimentalnom delu teze detaljno je analizirano pet uzoraka devičanskih maslinovih ulja-DMU proizvedenih na različitim maslinarskim područjima Libije tokom dve uzastopne proizvodne godine. Krakteristike ovih ulja su upoređene sa karakteristikama ekstra devičanskih maslinovih ulja najpoznatijih svetskih proizvođača, Italije. Španije i Grčke. Najvažnije masne kiseline u maslinovom ulju su sedam glavnih masnih kiselina- MK koje su detektovane u uzorcima DMU. Oleinska, palmitinska i linolna kiselina su dominantne, dok su druge MK detektovane u malim količinama.Najveći procenat palmitinske kiseline nadjen je u DMU sa područja Tripoli (P ≤ 0,05). Oleinska kiselina je dominantna u svim uzorcima DMU.Ustanovljeno je da je Libijsko DMU sa područja Gharyan poseduje najvišu koncentraciju oleinske kiseline, mononezasićenih masnih kiselina, najviši sadržaj bioaktivnih jedinjenja i najbolju nutritivnu vrednost.Bioaktivna jedinjenja u maslinovom ulju su tokoferoli, fenoli i pigmenti. Ova jedinjenja čine maslinovo ulje veoma zdravim. Ispitivana je, takođe, i fotostabilnost DMU pod uticajem fluorescentnog svetla u periodu od 35 dana. Ovi eksperimenti su sprovedeni sa tri uzorka DMU sa poreklom iz Libije u poređenju sa uljem iz Italije. Uzorci su bili izloženi fluorescentnom svetlu u providnoj i tamno smeđoj staklenoj ambalaži. Posmatrane su izmene karakteristika boje i rezultati su pokazali da fluorescentna svetlost utiče na smanjenje kvaliteta DMU više u uzorcima u transparentnoj ambalaži u poređenju sa onima u tamno smeđoj ambalaži.Osim toga, ispitana je i termostabilnost boje DMU primenom Schaal-Oven testa pod uticajem umerene temperature od 63 ± 2°C tokom perioda od 28 dana. Najmanje promene karakteristika i parametri najboljeg kvaliteta zabeležene su uzorku Gharyan DMU. Uzorak je sadržavao više pigmenata i fenolnih jedinjenja u poređenju sa uzorkom iz Italije i gubitak je bio najmanji za parametre boje. Pozitivna veza između jodnog broja i polinezasićenih masnih kiselina je registrovana sa koeficijentom korelacije r = +0,927. Primećena je i snažna pozitivna veza između sadržaja hlorofila i (a*) vrednosti boje, (r = + 0,859). Snažna pozitivna veza između TPC i AC (1/EC50DPPH) je takodje primećena, r je bio + 0,511. S druge strane, (1/EC50DPPH) je pokazao pozitivnu umerenu korelaciju sa TTC, (r = + 0,587).

In this thesis, with the help of literature data, the geographical origin of olive and olive oil, its use during history, production process, sensory properties, nutritive value and composition of fatty acids and sustainability were presented. In the experimental part of the thesis, five samples of virgin olive oils-VOO produced in various olive growing regions of Libya were analyzed in detail over the two consecutive production years. The qualities of these oils are compared with the characteristics of extra virgin olive oils of the world's most famous producers, Italy. Spain and Greece. The most important fatty acids in olive oil are the seven major fatty acids - FA that are detected in the VOO samples. Oleic, palmitic and linolenic acid are dominant, while other FAs are detected in small amounts. The largest percentage of palmitic acid was found in the VOO from the Tripoli area (P ≤ 0.05). Oleic acid is dominant in all VOO samples. It has been found that the Libyan VOO from the Gharyan region has the highest concentration of oleic acid, monounsaturated fatty acids, the highest content of bioactive compounds and the best nutritional value. Bioactive compounds in olive oil are tocopherols, phenols and pigments. These compounds make olive oil very healthy. The VOO's photostability under the influence of fluorescent light for a period of 35 days was also examined. These experiments were carried out with three samples of VOO originating in Libya in comparison with oil from Italy. Samples were exposed to fluorescent light in transparent and dark brown glass containers. Changes in color characteristics were observed and the results showed that fluorescent light influences the quality of VOO more in samples in transparent packaging compared to those in dark brown packaging. In addition, the VOO color thermostability was tested using a Schaal-Oven test under the influence of a moderate temperature of 63 ± 2°C over a period of 28 days. The smallest changes in characteristics and parameters of the best quality were recorded in the Gharyan VOO sample. The sample contained several pigments and phenolic compounds compared to the sample from Italy and the loss was the smallest for the color parameters. The positive relationship between iodine and polyunsaturated fatty acids is registered with the coefficient of correlation r = + 0.927. A strong positive relationship between the content of chlorophyll and (a*) of the color value was noted, (r = + 0.859). A strong positive association between TPC and AC (1/EC50DPPH) was also observed, r was + 0.511. On the other hand, (1/EC50DPPH) showed a positive moderate correlation with TTC, (r = + 0.587).