Maščobnokislinska sestava čokolade ter vpliv temperaturnega režima na fazne prehode

Kopač, Tomaž (author), Vidrih, Rajko (mentor), Prislan, Iztok (comentor)

Namen magistrskega dela je bil ugotoviti sestavo maščobnih kislin vzorcev čokolade in lastnosti faznih prehodov s pomočjo plinske kromatografije (GC) in diferenčne dinamične kalorimetrije (DSC). Preučili smo 22 različnih čokolad, ki so na voljo na slovenskem trgu. Čokolade so bile razdeljene v 4 skupine glede na njihovo sestavo: Temna, Mlečna, Bela in Nerazvrščena. Rezultati obeh analiz so bili statistično ovrednoteni z linearno diskriminacijsko analizo (LDA). Maščobnokislinska sestava je pokazala, da so imele čokolade v skupini Temna najvišjo vsebnost stearinske kisline ter najnižjo vsebnost srednjeverižnih maščobnih kislin. Najvišje vrednosti srednjeverižnih maščobnih kislin in nenasičenih maščobnih kislin pa so bile izmerjene v skupini Nerazvrščeno. Metoda DSC je pokazala, da ima skupina Temna najvišje temperature ter najvišje vrednosti entalpije faznih prehodov. Skupini Mlečna in Bela pa imata najnižjo vrednost entalpije. Najnižja temperatura faznih prehodov je bila izmerjena v skupini Nerazvrščeno. Statistična analiza LDA je potrdila korelacijo med različnimi parametri faznega prehoda ter sestavo maščobnih kislin.

• Language: Slovenian
• Keywords: čokolada, maščobne kisline, fazni prehodi, kristalizacija, taljenje, plinska kromatografija, diferenčna dinamična kalorimetrija
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [T. Kopač]
• Year: 2024
• PID: 20.500.12556/RUL-166220
• UDC: 663.91:543.635.3
• COBISS.SI-ID: 220708355
• Publication date in RUL: 25.12.2024

Secondary language

• Language: English
• Title: Fatty acid composition of chocolate and the effect of temperature regime on phase transitions

Abstract

The aim of this master's thesis was to determine the fatty acid composition of chocolate samples and the properties of phase transitions using gas cromatography (GC) and differential scanning calorimetry (DSC). We examined 22 various chocolates available on the Slovenian market. The chocolates were divided into 4 groups according to their composition: Dark, Milk, White and Unclassified. The results of both analyses were statistically evaluated using linear discriminant analysis (LDA). In terms of fatty acid composition, the chocolates in the Dark group had the highest stearic acid content and the lowest medium-chain fatty acid content. The highest levels of medium-chain fatty acids and unsaturated fatty acids were measured in the Unclassified group. The DSC method showed that the Dark group had the highest phase transition temperature and the highest enthalpy values. The Milk and White groups have the lowest enthalpy. The lowest phase transition temperature was measured in the Unclassified group. The statistical LDA analysis confirmed the correlation between different parameters from phase transition and fatty acid composition.

• Keywords: chocolate, fatty acids, phase transitions, crystalization, melting, gas cromatography, differential scanning calorimetry