No public access
master's thesis
Evaluation of maldi-tof technology in olive oil adulteration

Ana-Marija Jergović (2016)
Sveučilište u Rijeci
Odjel za biotehnologiju
Metadata
TitleEvaluacija maldi-tof tehnologije u otkrivanju krivotvorenja maslinovog ulja
AuthorAna-Marija Jergović
Mentor(s)Sandra Kraljević Pavelić (thesis advisor)
Abstract
Krivotvorenje ekstra djevičanskog maslinovog ulja (EDMU) sa drugim biljnim uljima česti je problem na današnjem tržištu maslinovih ulja. U ovom je radu stoga provedena evaluacija učinkovitosti metode za analizu lipida MALDI-TOF/MS u dokazivanju krivotvorenja EDMU. Ovo istraživanje temelji se na identifikaciji triacilglicerola (TAG) koji su karakteristični za svako biljno ulje i koji ulaze u sastav ispitivanih ulja: EDMU, jestivog suncokretovog ulja (S) i maslinovog ulja sastavljenog od rafiniranih maslinovih ulja i djevičanskih maslinovih ulja (R). Analiza MALDI-TOF/MS provedena je u svrhu detektiranja krivotvorenog EDMU sa S i R, u različitim omjerima (1%, 10% i 20%) izraženim kao postotak mase (%w/w). Za određivanje krivotvorenog EDMU provedeno je istraživanje i zakonski propisanih pokazatelja K vrijednosti kvalitete ulja. Rezultati upućuju kako se dodatak 1% biljnih ulja u EDMU može zamijetiti uz pomoć tehnologije MALDI-TOF/MS, iako je za potpuno dokazivanje bilo potrebno provesti i statističku analizu. Na temelju K270 vrijednosti bilo je moguće detektirati dodatak 10% S i R u EDMU, dok je ΔK vrijednost potvrdila dodatak 20% R u EDMU. Metodom DPPH ispitan je i antioksidacijski kapacitet svih uzoraka, dok je sadržaj ukupnih fenola određen metodom Folin-Ciocalteu u svrhu analize utjecaja krivotvorenja na antioksidacijsku stabilnost ulja. Rezultati upućuju na značajno veći antioksidacijski kapacitet i udio ukupnih fenola EDMU u usporedbi s uzorcima R i S, dok je u uljnim mješavinama zamijećeno blago opadanje spomenutih parametara. Metoda analize glavnih komponenata (PCA) uz rezultate masene spektrometrije o zastupljenosti TAG, omogućila je izdvajanje različitih kategorija ulja i detektirala dodatak 1% S i R u EDMU. Izdvajanjem EDMU od ostalih uzoraka, pokazan je jedinstven sastav TAG EDMU u usporedbi sa drugim uzorcima ulja. Klaster analizom utvrđena je mala udaljenost povezanosti EDMU i njegovih mješavina, te značajna udaljenost povezanosti EDMU sa S i R.
KeywordsExtra virgin olive oil adulteration MALDI-TOF/MS triacylglycerols
Parallel title (English)Evaluation of maldi-tof technology in olive oil adulteration
Committee MembersSandra Kraljević Pavelić (committee chairperson)
Mirela Sedić (committee member)
Mladenka Malenica Staver (committee member)
GranterSveučilište u Rijeci
Lower level organizational unitsOdjel za biotehnologiju
PlaceRijeka
StateCroatia
Scientific field, discipline, subdisciplineBIOTECHNICAL SCIENCES
Biotechnology
Study programme typeuniversity
Study levelgraduate
Study programmeBiotechnology in medicine
Academic title abbreviationmag. biotech. in med.
Genremaster's thesis
Language Croatian
Defense date2016-09-15
Parallel abstract (English)
Adulteration of extra virgin olive oil (EVOO) with other vegetable oils is a common problem that occurs at today's olive oil world market. Hence, in this research the evaluation of method for lipid analysis MALDI-TOF/MS's effectivness has been investigated in order to detect adulterated EVOO. The research is based on the identification of triacylglycerols (TAG) which are specific for composition of EVOO, edible sunflower oil (S) and olive pomace oil (R). Analysis of MALDI-TOF/MS is conducted for the purpose of detecting adulterated EVOO with S and R in different ratios (1%, 10% i 20% w/w). The research of legally prescribed indicators K values has been conducted for determination of olive oil quality and adulterated EVOO detection. Results suggest that 1% addition of vegetable oils in EVOO can be noticed with MALDI-TOF/MS technology, although a performed statistical analysis was also necessary for its complete confirmation. Based on K270 value it was possible to detect addition of 10% S and R in EVOO, while ΔK value confirmed addition of 20% R in EVOO. Antioxidant capacity of all samples was determined by DPPH method and eastimation of total phenolic content was examined by Folin-Ciocalteu method. This was carried out to examine the impact of adulteration on oil antioxidant stability. Results suggest significantly higher antioxidant capacity and total phenolic content of EVOO in comparison to samples of R and S, while in oil mixtures was noted mild decrease in these parameters. Principal component analysis method (PCA) using mass spectrometry results of the main TAG present in oils, made possible to separate different category of oils and detect addition of 1% S and R in EVOO. This analysis discriminated EVOO from other samples and that confirmed the unique TAG of EVOO composition compared with other samples. Cluster analysis determined small distance among the cluster members (EVOO and oil mixtures) and significant distance between EVOO and other samples S and R.
Parallel keywords (Croatian)Ekstra djevičansko maslinovo ulje krivotvorenje MALDI-TOF/MS triacilgliceroli
Resource typetext
Access conditionNo public access
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:193:091703
CommitterLea Lazzarich