Analiza izdelkov s področja prehrane z rentgensko praškovno difrakcijo

Bušljeta, Lara (author), Golobič, Amalija (mentor)

V diplomskem delu sem preučevala različne prehranske izdelke, npr. sladila, pecilni prašek, dekorativni izdelki za pecivo ipd. Uporabila sem metodo rentgenske praškovne difrakcije. Ta metoda temelji na uklanjanju rentgenskih žarkov na kristaliničnih snoveh. To so snovi z urejeno notranjo zgradbo (redom dolgega dosega), saj se motiv osnovne celice periodično ponavlja v vseh treh smereh prostora. Za analizo torej potrebujemo trdne kristalinične vzorce. Dobljeni sliki pravimo difraktogram in je značilen za vsako kristalinično snov, kot prstni odtis pri človeku. Pri kvalitativni analizi sem uporabila programa X'pert HighScore Plus za pretvorbo datotek v berljivo obliko in Crystallographica Search-Match za identifikacijo faz. Nato sem v programu TOPAS z Rietveldovo metodo določila še masne deleže identificiranih komponent vzorca. Ugotovila sem, da vsebuje večina testiranih vzorcev vsaj eno vrsto sladkorja, najpogosteje saharozo. Pogosta sestavina je še natrijev hidrogenkarbonat. Obe sestavini sta poceni, zato ju produkti vsebujejo v precejšnjem deležu. Kar nekaj sestavin z deklaracij pa tudi nisem mogla identificirati, bodisi ker so bile dodane k izdelku v zelo majhnih količinah in so bili njihovi ukloni skriti v ozadju ali ker so to amorfne snovi ali pa njihovi standardi niso vključeni v PDF podatkovni zbirki.

• Language: Slovenian
• Keywords: rentgenska praškovna difrakcija, kvalitativna in kvantitativna fazna analiza, prehranski izdelki
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2024
• PID: 20.500.12556/RUL-160433
• COBISS.SI-ID: 206628611
• Publication date in RUL: 28.08.2024

BUŠLJETA, Lara, 2024, Analiza izdelkov s področja prehrane z rentgensko praškovno difrakcijo [online]. Bachelor’s thesis. [Accessed 17 May 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=160433

Secondary language

• Language: English
• Title: Analysis of food products by X-ray powder diffraction

Abstract

In my thesis, I studied various food products, e.g. sweeteners, baking powder, decorative products for pastries, etc. I used the X-ray powder diffraction method. This method is based on the reflection of X-rays on crystalline substances, i.e. substances with an ordered internal structure, the motif of the unit cell is periodically repeated in all three directions of space. We therefore need solid crystalline samples for analysis. The resulting image is called a diffractogram and is characteristic of every crystalline substance, like fingerprints for people. In the qualitative analysis, I used the X'pert HighScore Plus program to convert the files into a readable format and Crystallographica Search-Match to identify the phases. Then I determined the mass fractions of the identified components of the sample using the Rietveld method in the TOPAS program. I found that most of the samples tested contained at least one type of sugar, usually sucrose. Another common ingredient is sodium bicarbonate. Both ingredients are cheap, so the majority of products contain them. Unfortunately, I was unable to identify quite a few ingredients from the ingredients list, either because they were added to the product in very small quantities and their diffraction peaks were hidden in the background, or because they are amorphous substances or maybe even because their standards are not included in the PDF database.

• Keywords: X-ray powder diffraction, qualitative and quantitative phase analysis, food products