Primjena NIR spektroskopije u detekciji glutena kao kontaminanta hrane

master's thesis

• Title (english): Application of NIR spectroscopy in gluten detection as a contaminant in food
• Author: Marija Radman
• 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: 2018-07-18, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Nutrition

Abstract

Kada je riječ o kontaminaciji hrane, kontaminacija glutenom posebno dolazi do izražaja. Kontaminirana može biti i hrana koja prirodno ne sadrži gluten, pa čak i hrana s oznakom „bez glutena“. Zbog zaštite zdravlja osoba koje ne smiju konzumirati gluten, od iznimne je važnosti određivanje i pravilno označavanje bezglutenske hrane. Cilj ovog rada bio je ispitati primjenu NIR spektroskopije u detekciji glutena u riži, rižinom i kukuruznom brašnu te kukuruznoj krupici. U tu svrhu korištene su dvije vrste pšeničnih brašna i dodavane u hranu u postotku od 5% do 30%. Pripremljene su tri vrste uzoraka, a svi uzorci mjereni su u rasponu valnih duljina od 904 nm do 1699 nm. NIR spektroskopija je kombinirana s analizom glavnih komponenta (PCA) koja je korištena za otkrivanje sličnosti i razlika između uzoraka. U svrhu razvijanja modela predikcije postotka brašna u uzorcima, korištena je linearna regresija te je dobiveno 9 primjenjivih modela s koeficijentom determinacije iznad 0,9. Nadalje, praćena je vodljivost i ukupne otopljene tvari (TDS) kako bi se istražile razlike u uzorcima. Svi uzorci, osim kombinacije kukuruznog i oštrog brašna, pokazali su linearni rast vodljivosti i TDS-a povećanjem postotka brašna. Da bi se utvrdio sadržaj glutena u pšeničnim brašnima i uzorcima, sadržaj vlažnog glutena određen je metodom ručnog ispiranja, a sadržaj suhog glutena sušenjem vlažnog glutena. Svjetlosna mikroskopija korištena je za određivanje veličine i oblika čestica u korištenim sirovinama.

Abstract (english)

When it comes to food contamination, gluten contamination is particularly pronounced. Contaminated can also be foods that naturally do not contain gluten, and even food labeled"glutenfree". For the health of people who should not consume gluten, it is important to determine and correctly label gluten-free foods. The aim of this work was to determine the applicability of the NIR spectroscopy for detection of gluten in rice, rice flour, corn flour and corn grits. For that purpose, two types of wheat flours were used and added to food in a percentage from 5% to 30%. Three types of samples were made, and all samples were recorded from 904 nm to 1699 nm. NIR spectroscopy was combined with principal component analysis (PCA) which is used to detect similarities and differences between samples. In order to develop model that predicts percentage of the flour in the samples, linear regression was used, which resulted with 9 applicable models, with the coefficient of determination above 0,9. Furthermore, conductivity and total dissolved solids (TDS) were monitored to determine changes in samples. All samples, except combination of corn flour and hard wheat flour, showed linear growth of conductivity and TDS with the increase of flour percentage. To determine gluten content in wheat flours and samples, wet gluten content was determined by manual method and dry gluten content by drying wet gluten. Light microscopy was used to determine size and shape of particles in used materials.

• Keywords: NIR spektroskopija; gluten; pšenično brašno; kukuruz; riža
• Keywords (english): NIR spectroscopy; gluten; wheat flour; corn; rice
• Language: croatian
• URN:NBN: urn:nbn:hr:159:172755
• Study programme: Title: Nutrition; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra nutricionizma (magistar/magistra nutricionizma)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-12-02 12:02:29