Določanje maščobnih kislin v pekovskih izdelkih s plinsko kromatografijo

diplomsko delo

Melita Novak (Author), Helena Prosen (Mentor)

Abstract

Namen mojega diplomskega dela je bil določanje celokupne vsebnosti maščobnih kislin v pekovskih izdelkih s slovenskega in srbskega tržišča ter ugotavljanje vsebnosti trans-maščobnih kislin. Na slovenskem trgu je najvišja dovoljena vsebnost trans-maščobnih kislin na 2 g na 100 g celokupnih maščob. Primerjala sem ekstrakcijo maščobe z Weibull-Stoldt-ovo metodo in metodo z uporabo MAK174 pribora. Delež ekstrahirane maščobe pri Weibull-Stoldt-ovi metodi je okoli 25 % (m/m), pri uporabi MAK174 pribora pa povprečno 10 % (m/m). Vzorce sem analizirala s plinsko kromatografijo s plamensko-ionizacijskim detektorjem. Priprava ekstrakta za GC-FID analizo vključuje derivatizacijo ekstrahirane maščobe iz vzorca v hlapne metilne estre maščobnih kislin. Analiza je potekala na močno polarni koloni HP-88, kjer so se metilni estri maščobnih kislin ločili glede na dolžino verige, nenasičenost, cis/trans izomerizacijo in pozicijo dvojne vezi. Spojine v vzorcih sem identificirala glede na retencijske čase pri predhodno optimizirani kromatografski metodi, ki omogoča ustrezno ločbo C18:2 in C18:3 maščobnih kislin. Kvantitativna določitev, ki vključuje tudi pripravo vzorca, ima visoko ponovljivost.

Keywords

pekovski izdelki;lipidi;maščobne kisline;metilni estri;analizne metode;plinska kromatografija;diplomska dela;

Data

Language:	Slovenian
Year of publishing:	2020
Typology:	2.11 - Undergraduate Thesis
Organization:	UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher:	[M. Novak]
UDC:	543.544.3:664.66(043.2)
COBISS:	23473667
Views:	794
Downloads:	218
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Determination of fatty acids in bakery products by gas chromatography
Secondary abstract:	The aim of this thesis is the determination of total fatty acid content in bakery products from Slovenian and Serbian market and quantification of trans-fatty acids. The maximum amount of trans-fatty acids on Slovenian market is 2g per 100 g of total fat content. Two fat extraction methods were compared: Weibull-Stoldt method and extraction by MAK174 kit. The Weibull-Stoldt method gives approximately 25 % (m/m), while MAK174 kit only allows extracting 10 % (m/m) on average. The samples were analysed by gas chromatography with flame-ionization detector. Extract preparation for GC-FID analysis includes derivatization of extracted fat from a sample to volatile methyl esters of fatty acids. The analysis was performed on a highly polar HP-88 column, which allows separation of fatty acid methyl esters according to the length of chain, unsaturation, cis/trans isomerization and the double bond position. Compounds in the samples were identified based on retention times acquired with a previously optimized chromatographic method, which allows a better separation of C18:2 and C18:3 fatty acids. Quantitative determination, which includes sample preparation as well, has a great repeatability.
Secondary keywords:	gas chromatography;fatty acids;methyl esters;bakery products;
Type (COBISS):	Bachelor thesis/paper
Study programme:	1000373
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, UNI Kemija
Pages:	XII, 32 f.
ID:	11893734