diplomsko delo
Neža Ožbold (Author), Tomaž Požrl (Reviewer), Tomaž Polak (Mentor)

Abstract

Namen diplomskega dela je bil določiti vsebnost kofeina v temnih čokoladah na slovenskem trgu. Omejili smo se na analizo temnih čokolad z deklariranim kakavovim deležem nad 50 %. Najvišjo vsebnost kofeina (0,45 %) smo določili v vzorcu temne čokolade znamke Moser roth z deklarirano vsebnostjo kakavovih delov najmanj 70 %. Najnižjo (0,12 %) pa smo določili v vzorcu temne čokolade znamke Lindt z deklarirano vsebnostjo kakavovih delov najmanj 70 %. Dobljeni rezultati so primerljivi z literaturo. Ugotovili smo, da obstaja korelacija med deklarirano vsebnostjo kakavovih delov in določeno vsebnostjo kofeina pri vzorcih temne čokolade znamke Lindt. Vsebnost kofeina linearno narašča z deležem kakavovih delov. Pri ostalih znamkah takšne korelacije ni, kar je verjetno posledica uporabe kakava različnega izvora. Domnevamo, da je različna vsebnost kofeina v vzorcih temne čokolade verjetno odvisna od geografskega porekla kakava. V vzorcih temne čokolade smo določali 49 različnih maščobnih kislin, od tega jih je bilo 19 pod mejo detekcije (< 0,001 % od skupnih MK) pri vseh vzorcih. V povprečju so v vzorcih temne čokolade kvantitativno najpomembnejše: stearinska kislina (C 18:0), katere povprečna vsebnost je 34,83 % od skupnih MK, oleinska kislina (C 18:1 c9), katere povprečna vsebnost je 32,19 % od skupnih MK, palmitinska kislina (C 16:0), katere povprečna vsebnost je 25,89 % od skupnih MK in linolna kislina (C 18:2 c9-12), katere povprečna vsebnost je 3,08 % od skupnih MK. V vzorcih temne čokolade smo določili relativno visok odstotek maščobe (od 46,25 % do 66,72 %). Prav tako sta visoka odstotka nasičenih MK (od 28,85 % do 41,59 %) in enkrat nenasičenih MK (od 13,35 % do 22,14 %). Odstotek trans MK pa je relativno nizek (od 0,03 % do 0,14 %).

Keywords

kakavovec;temna čokolada;tehnološki postopki;kofein;maščobnokislinska sestava;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [N. Ožbold]
UDC: 663.91:547.857.4:543.635.3
COBISS: 5091448 Link will open in a new window
Views: 1052
Downloads: 335
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Other data

Secondary language: English
Secondary title: Caffeine content in dark chocolate
Secondary abstract: The aim of graduation thesis was to determine the caffeine content of dark chocolate on the Slovenian market. We restricted ourself to analyzing dark chocolates with a declared cocoa content of more than 50%. The highest caffeine content (0.45%) was determined in a Moser roth dark chocolate sample with a declared cocoa content of at least 70%. The lowest (0.12%) was determined in a Lindt dark chocolate sample with a declared cocoa content of at least 70%. The results obtained are comparable with the literature. We found that there was a correlation between the declared cocoa content and the specific caffeine content of Lindt dark chocolate samples. Caffeine content increases linearly with the proportion of cocoa parts. For other brands, there is no such correlation, which is probably due to the use of cocoa of different origin. It is suggested that the different levels of caffeine in dark chocolate samples may depend on the geographical origin of the cocoa. In the dark chocolate samples, 49 different fatty acids were determined, 19 of which were below the limit of detection (<0.001% of total fatty acids) in all samples. On average, dark chocolate samples are quantitatively most important: stearic acid (C 18: 0), whose average content is 34.83% of total fatty acids, oleic acid (C 18: 1 c9), whose average content is 32.19% of total fatty acids, palmitic acid (C 16: 0) whose average content is 25.89% of total fatty acids and linoleic acid (C 18: 2 c9-12) whose average content is 3.08% of total fatty acids. We determined a relatively high percentage of fat (from 46.25% to 66.72%) in dark chocolate samples. The percentages of saturated fatty acids (from 28.85% to 41.59%) and once unsaturated fatty acids (from 13.35% to 22.14%) are also high. However, the percentage of trans fatty acids is relatively low (from 0.03% to 0.14%).
Secondary keywords: cocoa tree;dark chocolate;technological procedures;caffeine;fatty acid composition;
Type (COBISS): Bachelor thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: VIII, 23 f., [20] str. pril.
ID: 11217821