Primjena tekućinske kromatografije i elektrokemijskih biosenzora u određivanju niskomolekulskih organskih kiselina u fermentiranim mliječnim proizvodima

master's thesis

• Title (english): Application of high performance liquid chromatography and electrochemical biosensors for determinatination of low molecular weight organic acids in fermented dairy products
• Author: Nataša Živković
• Mentor: Damir Iveković (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: 2012-02-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Određivanje niskomolekulskih organskih kiselina u fermentiranim mliječnim proizvodima bitno je s obzirom na činjenicu da te kiseline utječu na okus, teksturu i nutritivna svojstva proizvoda. S obzirom na kompleksni sastav uzorka, preferirana metoda njihova određivanja je tekućinska kromatografija visoke učinkovitosti (HPLC). U ovom radu za određivanje niskomolekulskih organskih kiselina u vodenim ekstraktima komercijalnih fermentiranih mliječnih proizvoda, korištena je podvrsta ionsko-izmjenjivačke kromatografije, temeljena na isključenju po naboju (IEC – Ion Exclusion Chromatography). Pored toga, za određivanje mokraćne kiseline u uzorcima korišten je i posebno konstruiran elektrokemijski biosenzor za urate, temeljen na katalitičkom sloju berlinskog modrila. Ugradnjom iona Ni2+ u kristalnu rešetku katalizatora, postignuta je hidrolitiĉka stabilnost berlinskog modrila u lužnatom području. Obje metode pokazale su se primjenjivima za analizu ciljanih analita, pri čemu je postignuto dobro slaganje u rezultatima analize mokraćne kiseline pomoću obje primijenjene metode.

Abstract (english)

Determination of low molecular weight organic acids in fermented dairy products is important because these acids affect the taste, texture and nutritional properties of the product. Regarding the complex composition of the sample, prefered method for their determination is high performance liquid chromatography (HPLC). In this study, ion exclusion chromatography is used for determination of low molecular weight organic acids, in water extracts of commercial fermented dairy products. Besides, special electrochemical biosensor, based on catalytic layer of prussian blue, was constructed and used for determination of uric acid in samples. Hydrolytic stabilization of prussian blue in alkaline conditions, was achived by insertion of nickel ions in crystal lattice. Both methods showed as applicable for analysis of target analytes. Good correlation was established between results of uric acid content for both applied methods.

• Keywords: organske kiseline; fermentirani mliječni proizvodi; HPLC analiza; mokraćna kiselina; biosenzori
• Keywords (english): organic acids; fermented dairy products; HPLC analysis; uric acid; biosensor; prussian blue
• Language: croatian
• URN:NBN: urn:nbn:hr:159:331675
• Study programme: Title: Food Safety Management; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka upravljanja sigurnošću hrane (magistar/magistra inženjer/inženjerka upravljanja sigurnošću hrane)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-06-01 10:58:16