Polifenolni spojevi i antioksidacijski kapacitet kadulje (Salvia officinalis L) s mediteranskog dijela Republike Hrvatske

master's thesis

• Title (english): Polyphenols and antioxidant capacity of sage (Salvia officinalis L.) from Mediterranean part of Croatia
• Author: Ivana Milanović
• Mentor: Verica Dragović-Uzelac (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Technology of Fruits and Vegetables Preservation and Processing); Zagreb
• Defense date and country: 2009-06-01, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U četiri uzorka kadulje ubrana na mediteranskom dijelu Hrvatske (Pirovac, Brač, Lošinj) istraživana je količina ukupnih polifenola (TP), pojedinačnih fenolnih kiselina, flavonoida i antioksidacijskog kapaciteta (AOC). Polifenolni spojevi ekstrahirani su primjenom konvencionalnih otapala (CE) te ekstrakcije potpomognute mikrovalovima (MAE). TP su određeni spektrofotometrijski metodom s Folin–Ciocalteu reagensom, fenolne kiseline (siringinska, vanilinska, kafeinska i ružmarinska kiselna te njihovi derivati, luteolin- te apigenin- glikozidi) određeni su HPLC UV-PDA metodom, a AOC FRAP metodom. Ekstrakcija fenola primjenom CE i MAE provedena je upotrebom triju otapala (voda, 30%-tna vodena otopina etanola i acetona). Najviše TP ekstrahirano je primjenom 30%-tne otopine acetona. Međutim prema HPLC UV/PDA analizi utvrđeno je da su u acetonskom ekstraktu izolirani spojevi koji ne pripadaju skupini polifenola, ali reagiraju sa Folin-Ciocalteu reagensom. Utvrđene su značajne razlike u koncentraciji pojedinačnih fenolnih spojeva te TP između uzoraka kadulje s tri različita lokaliteta. U acetonskom i etanolnom ekstraktu najviša koncentracija TP određena je u kadulji s područja Lošinja (52,30 odnosno 44,76 mg RAE g-1 suhog uzorka). Najzastupljeniji fenolni spoj u svim uzorcima kadulje bila je ružmarinska kiselina (od 60,15 do 74,12%), a potom slijede flavoni. Ekstrakcija polifenola potpomognuta mikrovalovima utječe ne povećanje koncentracije fenola, naročito u acetonskom i etanolnom ekstraktu (za kadulju s Lošinja 56,16 odnosno 49,49 mg RAE g-1 uzorka). Ekstrakcijski kapacitet ekstrakata dobivenih primjenom CE niži je u odnosu na ekstrakcijski kapacitet postignut primjenom MAE uz upotrebu istih otapala. U svim uzorcima određen je visok AOC, a najveće vrijednosti određene su u uzorcima kadulje s područja Lošinja. Visoki koeficijenti korelacije od 0,6865 do 0,9427 dokaz su dobre korelacije između koncentracije TP i AOC.

Abstract (english)

Total polyphenols content (TP), phenolic acids, flavonoids and antioxidant capacity (AOC) of four dry sage harvested at Mediterranean part of Croatia (Pirovac, Brač, Lošinj) extracted using conventional (CE) and microwave-assisted solvent extraction (MAE) methods were studied. TP were determined using spectrophotometric Folin-Ciocalteu method, phenolic acids (p-coumaric, vanillic, caffeic and rosmarinic acid and their derivate, luteolin and apigenin glicosydes) were determined using HPLC UV/PDA method and AOC using FRAP method. Three different solvents (water, 30 % aquous solution of ethanol or acetone) were used in the CE and MAE. The highest extraction capacity was observed using acetone solution. However, according to HPLC UV/PDA analysis it was observed that in acetone extract exist compounds that don't belong to polyphenols but react with Folin-Cioacalteu reagens. There was significant difference in the polyphenols contents among sage harvested at three different locations. In acetone and ethanolic extract the highest amount of TP was determined in sage from Lošinj (52, 30 and 44,76 mg RAE g-1 of dry sage, respectively). The main polyphenolic compound in all sage samples was rosmarinic acid (from 60,15 to 74,12% )followed by flavons. Microwave-assisted solvent extraction significantly increased the content of polyphenols; especially in acetone and ethanolic extract (sage from Island Lošinj has 56, 16 and 49, 49 mg RAE g-1 of dry sage, respectively). Furthermore, extraction capacity of conventional ethanol or acetone solvent was significantly lower than microwave-assisted ethanol or acetone extractions. The high AOC in all sage samples was observed, and the highest values were determined in samples from Lošinj. High correlation factor (from 0,6865 to 0,9427) showed evident correlation between TP and AOC.

• Keywords: Kadulja; fenolni spojevi; antioksidacijski kapacitet; ekstrakcija; HPLC metoda
• Keywords (english): sage; polyphenols; antioxidant capacity; extraction; HPLC method
• Language: croatian
• URN:NBN: urn:nbn:hr:159:359443
• Study programme: Title: Food Technology; specializations in: Food Engineering; Course: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo (diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-08-31 07:37:04