20.500.12556/RUL-124709 Vpliv sestave čokolade na njene reološke lastnosti Effect of chocolate composition on its rheological properties Končna struktura, stabilnost čokolade in senzorične lastnosti, ki jih zaznamo ob uživanju čokoladne tablice, so odvisni od vsebnosti sestavin in njihove količine, ter sprememb tekom proizvodnega procesa. Med proizvodnjo imamo opravka s čokolado v tekoči obliki, poznavanje njenih reoloških lastnosti pripomore k načrtovanju optimalnega proizvodnega procesa, prav tako je pomembno pri kontroli kakovosti vmesnih produktov in končnega izdelka. Viskoznost je ena pomembnejših reoloških lastnosti čokolade, saj v ustih določa zaznan okus. Reološke lastnosti čokolade se meri z rotacijskimi viskozimetri in reometri. Tekoča čokolada predstavlja nenewtonsko tekočino s strižno odvisnim upadanjem viskoznosti. Viskoznost in mejno napetost se iz tokovnih krivulj, ki jih pridobimo z meritvami, določi z uporabo matematičnih modelov; najpogosteje z uporabo Cassonovega modela. Na reološke lastnosti čokolade vpliva več dejavnikov; to so oblika, velikost in razporeditev trdnih delcev, prisotnost vlage, vsebnost maščobe, vsebnost površinsko aktivnih snovi in proces konširanja. V svojem diplomskem delu sem s pomočjo ustrezne literature proučila proizvodnjo in sestavo čokolade, kaj vse na tokovno obnašanje tekoče čokolade vpliva in kako se reološke meritve čokolade izvajajo ter analizirajo. S pomočjo meritev, povzetih iz objavljene raziskave v literaturi, sem proučila, kako sestava in struktura treh glavnih tipov čokolade (bela, mlečna in temna) vplivata na njihove reološke lastnosti. Final structure, stability and sensory properties of chocolate, that we sense during chocolate bar consumption, depend on the ingredients and their quantity; moreover these properties also change during chocolate manufacture. During the production the chocolate is in its liquid form, therefore the knowing of its rheological properties is necessary to develop an optimal manufacture process and also for quality control of intermediate and final products. Viscosity is one of the most important rheological properties of chocolate also for the consumer, because it determines the perceived taste in the mouth. Rheological properties of chocolate are measured with rotational viscometers and rheometers. Liquid chocolate is a non-newtonian fluid with shear thinning flow behaviour. Viscosity and yield stress are determined from flow curves, obtained by rheological measurements, with the use of mathematical models; usually with Casson model. There are several factors that influence rheological properties of chocolate; these are shape, size and distribution of solid particles, presence of moisture, content of fats, content of surface acting agents and the process of conching. With the help of technical literature I have studied the manufacture and composition of chocolate, what affects the flow of liquid chocolate and how are the rheological measurements carried out and the results analyzed. With the help of measurements, taken from a published research, I have studied the influence of the composition and structure of three main types of chocolate (white, milk and dark) on their rheological properties. sestava čokolade proizvodnja čokolade reološke lastnosti viskoznost composition of chocolate chocolate production rheology viscosity true false false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2021-02-11 10:00:01 2021-02-11 10:00:13 2022-09-04 04:00:59 0000-00-00 00:00:00 2021 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 11826 51608835 Uhelj_grca_Tjasa_-_Vpliv_sestave_cokolade_na_njene_reoloske_lastnosti.pdf Uhelj_grca_Tjasa_-_Vpliv_sestave_cokolade_na_njene_reoloske_lastnosti.pdf 1 387C9E34D27631F89C323DD131A58F86 a70f17646787075462b57d5f0c7f03f459a86968f830338f05fb76a437c0fe52 9b1c685e-a1bb-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=140276 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0