Mogućnost primjene Raman spektroskopije pri kontroli kvalitete ribe

doctoral thesis

• Title (english): Possible applications of Raman spectroscopy in fish quality control
• Author: Tibor Janči
• Mentor: Sanja Vidaček (mentor)
• Committee member: Helga Medić (predsjednik povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; Zagreb
• Defense date and country: 2016-12-23, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology
• Universal decimal classification (UDC): 59 - Zoology

Abstract

Cilj ovog istraživanja bio je ispitati mogućnost primjene Ramanove spektroskopije pri detekciji histamina, geosmina i 2-metilizoborneola u mesu ribe te razviti brzu metodu detekcije i kvantifikacije navedenih spojeva primjenom spektroskopije površinski pojačanog Ramanovog raspršenja (SERS). Sintetizirano je i ispitano 6 koloidnih suspenzija nanočestica srebra, 11 SERS supstrata srebrnog filma preko nanosfera (AgFON) te 11 AgFON supstrata funkcionaliziranih metalo-organskim mrežama. Najbolji rezultati pri detekciji histamina postignuti su kombinacijom srebrnog koloida reduciranog citratnim ionima u kombinaciji s otopinom NaBH4 koncentracije 0,23 mol L-1 kao agregirajućim sredstvom pri valnoj duljini pobude 514,5 nm. Niti jedan od ispitanih supstrata nije omogućio detekciju geosmina i 2-metilizoborneola. Razvijen je postupak pripreme uzorka ekstrakcijom pomoću perkloratne kiseline te naknadnog pročišćavanja ekstrakta 1-butanolom koji je omogućio snimanje spektra histamina u ekstraktima ribljeg mišićja. Konstruirano je i testirano više kalibracijskih modela metodama linearne regresije, prilagođavanja Langmuirove adsorpcijske izoterme eksperimentalnim podacima, analize glavnih komponenata (PCA) i parcijalne regresije metodom najmanjih kvadrata (PLS). Testiranje PLS modela potvrdilo je pouzdanost modela temeljenog na spektralnom području 1139,9 – 1643,7 cm-1 u rasponu koncentracije histamina 0 – 200 mg kg-1 (Rpred2 = 0,962, RPD = 7,250). Usporedba rezultata SERS metode i referentne HPLC metode pokazala je da je najveća točnost postignuta primjenom modela dobivenog linearnom regresijom na temelju intenziteta SERS vrpce histamina na 1264 cm-1. Razvijena metoda značajno je smanjila troškove kemikalija i opreme te skratila vrijeme potrebno za analizu (30 min) u usporedbi s referentnom HPLC metodom (140 min).

Abstract (english)

This study was focused on examining the possibility of detection of histamine, geosmin and 2-methylisoborneol in fish and development of rapid analytical method for quantification of targeted compounds by Surface Enhanced Raman Spectroscopy (SERS). 6 silver colloid, 11 silver film over nanospheres (AgFON) and 11 AgFON SERS substrates functionalized with metal-organic frameworks were prepared and tested. Best results regarding histamine detection were obtained with combination of citrate reduced colloid and 0,23 mol L-1 NaBH4 solution as aggregating agent at 514,5 nm excitation wavelength. Neither of the tested substrates enabled detection of geosmin and 2-methylisoborneol. Developed sample preparation protocol based on extraction with perchloric acid and subsequent purification of extract with 1-butanol enabled recording of histamine spectra in fish muscle extracts. Several calibration models were constructed by linear regression, Langmuir adsorption isotherm curve fitting, principal components analysis (PCA) and partial least squares regression (PLS). PLS regression models confirmed reliability of detection and spectral analysis of histamine with SERS. In histamine concentration range 0-200 mg kg-1 and for spectra range 1139,9 - 1643,7 cm-1, PLS regression showed linear trend with R2pred = 0,962, RPD = 7,250. Comparison of results with reference HPLC method proved that highest accuracy was obtained by linear regression model based on intensity of histamine SERS band at 1264 cm-1. Developed method significantly shortened analysis time (30 min) compared to HPLC method (140 min) and reduced operating and instrumentation costs.

• Keywords: riba; histamin; geosmin; 2-metilizoborneol; površinski pojačano Ramanovo raspršenje; Ramanova spektroskopija; kvantitativna analiza
• Keywords (english): fish; histamine; geosmin; 2-methylisoborneol; surface enhanced Raman scattering; Raman spectroscopy; quantitative analysis
• Language: croatian
• URN:NBN: urn:nbn:hr:159:705238
• Study programme: Title: Food Technology; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti (doktor/doktorica znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2018-05-17 12:33:49