Primjena plamene atomske apsorpcijske spektrometrije i kemometrijske analize za klasifikaciju uzoraka kave na osnovu sadržaja cinka, bakra, mangana i željeza

master's thesis

• Title (english): Application of flame atomic absorption spectrometry and chemometric analysis to classify coffee samples based on their zinc, copper, manganese and iron content
• Author: Iva Henčel
• Mentor: Jasna Jablan (mentor)
• Committee member: Jasna Jablan (predsjednik povjerenstva)
• Committee member: Suzana Inić (član povjerenstva)
• Committee member: Maja Bival Štefan (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of analytical chemistry); Zagreb
• Defense date and country: 2022-09-15, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Kava je jedan od najpopularnijih napitaka na svijetu. Pretpostavlja se da može biti značajan izvor mikrominerala kod osoba čija je konzumacija u većim količinama.
U sklopu ovog rada određen je sadržaj cinka, bakra, mangana i željeza u devetnaest različitih uzoraka kave pomoću FAAS, čijoj je analizi prethodila obrada uzoraka putem mokre digestije. Uzorci su podijeljeni u dvije osnovne skupine: kava s dodacima, koja se sastoji od sedam uzoraka i čista kava, koja se sastoji od dvanaest uzoraka.
Specifični cilj istraživanja bio je utvrditi moguću povezanost elementarnog sastava uzoraka kava s tipom kave putem kemometrijske obrade podataka koja je uključivala univarijantnu i multivarijantnu analizu. Univarijantna analiza pokazala je da se bakar, mangan i željezo mogu smatrati elementima koji prave najveću razliku među ispitivanim uzorcima. PCA analiza provedena je na svim uzorcima kave uključujući i varijable (analizirani elementi), gdje je grafika opterećenja pokazala blizak odnos između bakra i mangana, bakra i željeza, mangana i željeza te su određena dva značajna čimbenika povezana s izvorom elemenata u ispitivanim uzorcima kave. Klaster analiza primijenjena je za svrstavanje uzoraka u skupine na osnovu sličnosti elementarnog sastava. Dobiveni dendrogram pokazuje svrstavanje uzoraka kave u 4 glavne skupine gdje uzorci unutar iste skupine pokazuju sličnost po tipu kave s jednim izuzetkom. Uočena je dobra korelacija elementarnog sastava s tipom kave te istraživanje ukazuje na to da se ispitivane varijable mogu koristiti za razlikovanje vrste kave u smislu čiste kave i kave s dodacima.

Abstract (english)

Coffee is one of the most popular beverages in the world. It is believed that coffee can be a significant source of microminerals in people who consume it in larger quantites.
For the present work, samples were prepared by wet ashing and the composition of zinc, copper, manganese and iron in nineteen different coffee samples were quantified using FAAS. The samples were divided into two main groups according to their nature: Coffee with additives, comprising seven samples, and pure coffee, comprising twelve samples.
The specific objective of this work was to determine the possible relationship between the elemental composition of the samples and the coffee variety using chemometrics, which consisted of univariate and multivariate analysis. The univariate analysis showed that copper, manganese and iron accounted for the greatest difference between the samples. PCA analysis was performed for all samples, including the variables (of the elements analyzed), which showed a close association between copper and manganese, copper and iron, and manganese and iron; two main factors were identified and linked to the element source in the samples analyzed. Cluster analysis was performed to divide the samples into groups based on similarity of elemental composition, resulting in a division into four main clusters. In each cluster, the samples show good similarity between coffee types, leading to the conclusion that the analyzed variables can be used to distinguish coffee types, especially pure coffee and coffee with additives.

• Keywords: cink; bakar; mangan; željezo; plamena atomska apsorpcijska spektrometrija; kava
• Keywords (english): zinc; copper; manganese; iron; flame atomic absorption spectroscopy; coffee
• Language: croatian
• URN:NBN: urn:nbn:hr:163:274986
• Study programme: Title: Pharmacy; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra farmacije (magistar/magistra farmacije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2024-09-15
• Created on: 2022-09-16 08:47:59