UV-Vis i NMR analiza polifenolnih sastavnica maslinovih ulja

master's thesis

• Title (english): UV-Vis and NMR analysis of olive oil phenolic compounds
• Author: Matea Križanić
• Mentor: Cvijeta Jakobušić Brala (mentor)
• Committee member: Cvijeta Jakobušić Brala (predsjednik povjerenstva)
• Committee member: Monika Barbarić (član povjerenstva)
• Committee member: Viktor Pilepić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of physical chemistry); Zagreb
• Defense date and country: 2021-09-07, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Maslinovo ulje se, kao osnovna sastavnica mediteranske prehrane, dulji niz godina povezuje sa smanjenom učestalosti kroničnih upalnih bolesti, karcinoma te duljim životnim vijekom. Zbog pozitivnih učinaka na zdravlje, maslinovo ulje je danas sinonim zdravog načina prehrane. Pozitivan učinak posljedica je povoljnog sastava masnih kiselina, prije svega oleinske kiseline, te biološki aktivne polifenolne frakcije. Od pozitivnih učinaka može se istaknuti antioksidativna aktivnost, antikarcinogeni i imunomodulatorni učinak, kardioprotektivno djelovanje i antimikrobni učinak. Cilj ovog diplomskog rada bio je spektrofotometrijskim metodama sadržaj ukupnih fenola, flavonoida te o-difenola te 1H NMR spektroskopijom odrediti sadržaj polifenola oleokoronala, oleomisionala te S-(E)-elenolida, odabranih uzoraka hrvatskih maslinovih ulja. Sadržaj ukupnih polifenola određen je korištenjem Folin Ciocalteu reagensa, sadržaj ukupnih flavonoida korištenjem AlCl3 i NaNO2, a sadržaj o-difenola Na2MoO4 reagensa. Utvrđeno je da sadržaj polifenola varira od uzorka do uzorka u rasponu od 168-628 mg/kg, sadržaj flavonoida od 102-380 mg/kg te sadržaj o-difenola u rasponu od 184-596 mg/kg. Na temelju usporedbe sadržaja ukupnih polifenola, ukupnih flavonoida te o-difenola ispitana je ponovljivost metode ekstrakcije acetonitrilom. Utvrđena je dobra ponovljivost metode s pogreškom manjom od 4 %. Na isti način uspoređene su dvije metode ekstrakcije. Dobiveno je dobro slaganje u sadržaju flavonoida, dok je sadržaj polifenola acetonitrilnog ekstrakta bio značajno viši od sadržaja metanolnog ekstrakta. Uzorci priređeni postupkom ekstrakcije acetonitrilom nisu prikladni za određivanje o-difenola NaMoO4 reagensom. Metanolni ekstrakt se mora nužno analizirati neposredno nakon pripreme jer dolazi do promjene sastava tijekom čuvanja. Oleokoronal, oleomisional i S-(E)-elenolid su po prvi put određivani u hrvatskim maslinovim uljima. Sadržaj S-(E)-elenolida varira od uzorka do uzorka u rasponu od 40-910 mg/kg, sadržaj oleokoronala u rasponu od 63-162 mg/kg te sadržaj oleomisionala u rasponu od 36-169 mg/kg ulja.

Abstract (english)

Olive oil, as a basic component of the Mediterranean diet, has for long been associated with a reduced incidence of chronic inflammatory diseases and cancer as well as longer life expectancy. Due to its positive health effects, olive oil today is synonymous with healthy eating habits. The positive effect is due to the favorable fatty acid composition, primarily oleic acid, as well as biologically active polyphenolic fraction. Among positive effects, their antioxidant activity, anticarcinogenic, immunomodulatory, cardioprotective and antimicrobial effect can be highlighted. The purpose of this diploma thesis was to determine total phenolic, flavonoid and o-diphenol content by UV-Vis spectrophotometry and to determine content of S-(E)-elenolide, oleokoronal and oleomissional by 1H NMR spectrophotometry in selected samples of Croatian olive oils. Total phenolic content was determined using F-C reagent, total flavonoid content using AlCl3 and NaNO2, while o-diphenol content was determined using Na2MoO4. Total phenolic content varies in range 168-628 mg/kg, total flavonoid content in range 102-380 mg/kg and o-diphenol content in range 184-596 mg/kg of olive oil. Based on the comparison of the content of total polyphenols, total flavonoids and o-diphenols, the repeatability of the acetonitrile extraction method was examined. Good repeatability of the method with an error of less than 4% was found. Two extraction methods were compared in the same way. A good agreement was obtained in the flavonoid content, while the polyphenol content of the acetonitrile extract was significantly higher than the methanol extract content. Samples prepared by the acetonitrile extraction process were found to be unsuitable for the determination of o-diphenol with NaMoO4 reagent. Methanol extract has to be analysed immediately after the preparation as the content changes during storage. Content of oleokoronal, oleomisional and S-(E)-elenolide were determined, for the first time in Croatian olive oils. S-(E)-elenolide content varies in range 40-910 mg/kg, oleokoronal content in range of 63- 162 mg/kg and oleomisional cantent in range of 36-169 mg/kg of olive oil.

• Keywords: maslinovo ulje; UV-Vis spektroskopija; 1H NMR spektroskopija; polifenoli; o-difenoli; flavonoidi
• Keywords (english): olive oil; UV-Vis spectroscopy; 1H NMR spectroscopy; polyphenols; o-diphenols; flavonoids
• Language: croatian
• URN:NBN: urn:nbn:hr:163:123862
• Study programme: Title: Pharmacy; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra farmacije (magistar/magistra farmacije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-02-10 15:51:26