Usporedba metoda ekstrakcije polifenolnih spojeva u kaši drijenka (Cornus mas L.)

master's thesis

• Title (english): Comparison of extraction methods for polyphenols in cornelian cherry fruit (Cornus mas L.)
• Author: Maja Belačić
• 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: 2007-07-06, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Različite skupine fenolnih spojeva (antocijani, flavonol-glikozidi, flavan-3-oli, fenolne kiseline) nalaze se u različitim biljnim vrstama, a također i u drijenku (Cornus mas L.). U ovom radu istraživana je učinkovitost pojedinih metoda koje su provedene pomoću nekoliko različitih smjesa otapala i mogućnost primjene brze automatizirane metode ekstrakcije. Učinkovitost ekstrakcije svake metode je procjenjena usporedbom količine ukupnih fenola, određenih spektrofotometrijski primjenom Folin-Ciocalteu metode i fenolnih spojeva određivanih pomoću HPLC UV/VIS PDA metode. Korištenjem vodene otopine metanola ekstrahirana je najveća količina antocijana. Ekstrahirani antocijani su karakteristični za drijenak. Iz skupine antocijana u najvećoj koncentraciji identificiran je pelargonidin-3-galaktozid te cijanidin-3-galaktozid, a u padajućem nizu slijede cijanidin-3-glukozid, pelargonidin-3-glukozid i neidentificirani antocijan. Učinkovitost ekstrakcije fenolnih spojeva, osobito antocijana i flavonol-glikozida manja je ukoliko je ekstrakciji predhodila kiselinska hidroliza. Metoda u kojoj se kao otapalo koristila vodena otopina metanola (A2) pokazala se kao najpovoljnija metoda za ekstrakciju antocijana. Za ekstrakciju flavonoida i fenolnih kiselina kao najpovoljnija metoda pokazala se metoda u kojoj se koristila vodena otopina acetona (B2). Iz skupine fenolnih kiselina u najvećoj koncentraciji određena je vanilinska kiselina, a u padajućem nizu slijede galna kiselina, neoklorogenska kiselina, derivat hidroksicimetne kiseline, smjesa p-kumarinske i ferulinske kiseline i kava kiselina. Značajne skupine fenolnih spojeva predstavljaju i flavanoli među kojima se ističu (+)-katehin i (-)-epikatehin i skupina flavonol-glikozida među kojima se ističu kvercetin-3-glukozid i kvercetin-3-rutinozid.

Abstract (english)

Different group of phenolic compounds (anthocyanins, flavonol glycosides, flavan-3-ols, phenolic acids) exist in plant material and in cornelian cherry (Cornus mas L.), too. The extraction capacity of several solvent mixture and the possibility of employing rapid automated solvent extraction method were studied. The extraction yield of each method was evaluated by comparing total phenol content obtained using spectrophotometric Folin-Ciocalteu method and phenolic compounds determined by HPLC UV/VIS PDA method. Aqueous methanol extracted the highest amount of anthocyanins. Anthocyanins were determined as pelargonidin-3-galactoside (the highest concentration) and cyanidin-3-galactoside, cyanidin-3-glucoside, pelargonidin-3-glucoside and unidentified anthocyanin (the lowest concentration). The extraction yield of phenolic compounds, especially anthocyanins and flavonol glycosides decreased when acid hydrolysis was used. Most favorable method for extraction of anthocyanins was method which included the usage of aqueous methanol (A2). For extraction of flavonoids and phenolics acids most favorable method was method in which aqueous acethon was used for extraction (B2). The phenolic acids, determined in investigated samples by HPLC method, in decreasing sequence are: vanillic acid, galic acid, neochlorogenic acid, derivative of hydroxycinnamic acid, mixture of p-coumaric and ferulic acid and caffeic acid. From total polyphenols, flavonoids were determinate in significant quantities. Flavanols ((-)-epicatechin and (+)-catechin) and flavonol-glicozids (quercetin-3-glucoside and quercetin-3-futinoside) are significant groups of polyphenols and they were also determined by HPLC method.

• Keywords: Cornus mas; drijenak; fenolni spojevi; ekstrakcija; HPLC metoda
• Keywords (english): Cornus mas; cornelian cherry; polyphenols; extraction; HPLC method
• Language: croatian
• URN:NBN: urn:nbn:hr:159:680374
• 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: 2017-09-06 08:23:49