Primjena blisko-infracrvene spektroskopije u praćenju kakvoće bobičastog voća

master's thesis

• Title (english): Application of near-infrared spectroscopy to monitor the quality of wild berry fruit
• Author: Ivana Nebojan
• Mentor: Jasenka Gajdoš Kljusurić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Process Engineering); (Laboratory for Measurement, Regulation and Automatisation); Zagreb
• Defense date and country: 2013-09-30, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Ekstrakti bobičastog voća analizirani su primjenom blisko-infracrvene spektroskopije (NIRS) koja se može koristiti kao kvantitativna i kvalitativna metoda za detekciju, identifikaciju i razvrstavanje sirovina poput bobičastog voća te nadzirati njihovu kvalitetu. Praćeni su spektri voća mjereni difuznom trans-reflektancom i ti spektri su korišteni u kemometrijskoj analizi. Raspon NIR instrumenta korištenog u ovom istraživanju bio je od 904 - 1699 nm. Također je mjeren sadržaj ukupnih fenola, te je mjerena antioksidacijska aktivnost pomoću DPPH metode i Briggs-Rauscher-ove reakcije. Cilj rada bio je odrediti potencijal primjene infracrvene spektroskopije u međusobnom razlikovanju uzoraka (svježi ili stari 1 mjesec) kao i određivanje linearne veze među promatranim varijablama. Primijenjene su kemometrijske metode te je analiza NIR spektara ukazala na promjene u određenim valnim duljinama koje odgovaraju C-H kombinacijama i prvom overtonu navedene veze. Također je jednostavnim PLS modelom pokazana značajnost utjecaja skladištenja na NIR spektre (79%), a time i utjecaj na kvalitetu uzoraka koja opada ovisno o trajanju skladištenja. Ovo istraživanje je pokazalo kako NIR spektroskopija ima potencijal kao metoda koja može razlikovati uzorke prema načinu skladištenja, kao i za predikciju sadržaja ukupnih fenola i antioksidacijske aktivnosti prema određenim valnim duljinama spektra. Svi rezultati pokazuju svrhovitost korištenja NIR za on-line praćenje kvalitete proizvoda i njihove selekcije.

Abstract (english)

Berry extracts were analyzed using near-infrared spectroscopy (NIRS), which can be used as a quantitative and qualitative method for detection, identification and classification of raw materials such as berries and control their quality. Fruit spectra were monitored by measuring diffuse trans-reflectance and these spectra have been used in chemometric analysis. The range of the used NIR instrument ranged from 904 - 1699 nm. For the samples were also measured the contents of total phenols and the antioxidant activity using two methods: the DPPH method and Briggs-Rauscher's reaction. The aim of this study was to determine the potential application of infrared spectroscopy in distinguishing samples (fresh or 1 month old), and determining the linear relationship between the observed variables. Chemometrical methods were applied and the analysis of NIR spectra indicated changes in certain wavelengths corresponding to C-H combination and 1st overtone. Using simple PLS models was demonstrated the significance of the impact of storage on NIR spectra (79%), and thus the impact on the quality of the samples, which decreases depending on the duration of storage. This study showed that NIR spectroscopy has potential as a method that can differentiate samples by the sample quality (freshness or duration of storage), as well as to predict the total phenol content and antioxidant activity using specific wavelengths of the spectrum. All results show the usefulness of using NIRS for on-line monitoring of the quality of products and their selection.

• Keywords: bobičasto voće; NIR; DPPH; fenoli; BR reakcija
• Keywords (english): berries; NIR; DPPH; phenols; BR reaction
• Language: croatian
• URN:NBN: urn:nbn:hr:159:107506
• 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: 2017-05-05 12:03:13