Elektrokemijsko određivanje polifenola u vinima

master's thesis

• Title (english): Electrochemical determination of polyphenols in wines
• Author: Enis Hrustić
• Mentor: Božidar Grabarić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Chemistry and Biochemistry); (Laboratory for General and Inorganic Chemistry and Electroanalysis); Zagreb
• Defense date and country: 2005-07-11, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Elektrokemijsko određivanje polifenola u popularnim pićima (čajevi, crno i bijelo vino, kava, biljni likeri i ostalo) te ekstraktima prehrambenih namirnica temelji se na elektrokemijskoj oksidaciji polifenola na grafitnoj elektrodi. Obzirom da je jakost struje pri oksidacijskom potencijalu polifenola proporcionalna njihovoj koncentraciji, to svojstvo je iskorišteno za određivanje koncentracije polifenola u uzorcima. Odnos između koncentracija referentnog fenola, galne kiseline ili sličnog spoja npr. hidrokinona i jakosti struja pri oksidacijskim potencijalima u području mjerenih koncentracija polifenola ponekad nije linearan te za baždarni dijagram treba koristiti usklađivanje s polinomima trećeg ili višeg stupnja. Mjerenja su vršena diferencijalnom pulsnom voltametrijom. Rezultati određivanja polifenolnih spojeva diferencijalnom pulsnom voltametrijom uspoređeni su s rezultatima dobivenima spektrofotometrijskom standardnom metodom za određivanje ukupnih polifenola s Folin-Ciocalteauovim reagensom.

Abstract (english)

Electrochemical determination of polyphenols in popular beverages (tea, red wine, coffee and others) is based on electrochemical oxidation of polyphenols at graphite electrode. Thanks to proportional relation between current at oxidation potential of polyphenols and their concentration, electrochemical methods are proper for measuring samples. Relation between concentration of referent polyphenol, gallic acid or similar molecule eg. hidroquinone and currents at oxidation potential sometimes isn't linear, so aproximation by polynomials of the third and higher degree for working out calibration diagrams is needed. Polyphenols were measured by differential pulse voltametry. Results of differential pulse voltametry were compared with those obtained from standard spectrofotometric Folin-Ciocalteau method for determination of total polyphenols.

• Keywords: polifenoli; vino; diferencijalna pulsna voltametrija; standardne metode za ukupne polifenole
• Keywords (english): polyphenols; differential pulse voltametry; wine; standard methods for total polyphenols
• Language: croatian
• URN:NBN: urn:nbn:hr:159:009283
• Study programme: Title: Biotechnology; specializations in: Biochemical Engineering; Course: Biochemical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer biotehnologije; smjer biokemijsko inženjerstvo (diplomirani inženjer biotehnologije; smjer biokemijsko inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-13 11:22:52