magistrsko delo
Špela Žugič (Author), Tomaž Požrl (Reviewer), Nataša Šegatin (Mentor), Blaž Cigić (Co-mentor)

Abstract

V magistrskem delu smo raztopinam različnih saharidov določali dielektrične lastnosti. Analizirali smo vodne raztopine glukoze, fruktoze, inulina, dekstrina, maltodekstrina, oligofruktoze in glukozno-fruktoznega sirupa. Saharide smo okarakterizirali tako, da smo določili njihove reducirajoče lastnosti in v glukozno-fruktoznem sirupu delež fruktoze. Za določanje dielektrične konstante v območju frekvenc izmenične napetosti med 20 kHz in 2 MHz smo uporabili kapacitivno metodo in LCR merilnik. Zanimal nas je vpliv vrste saharida in temperature na dielektrične lastnosti različno koncentriranih raztopin. Dielektrična konstanta raztopin polisaharidov in faktor dielektričnih izgub se z naraščajočo frekvenco zmanjšujeta; dielektrična konstanta raztopin monosaharidov pa je v merjenem območju neodvisna od frekvence. Dielektrična konstanta raztopin saharidov pri 2 MHz se z naraščajočo temperaturo zmanjšuje, medtem ko specifična električna prevodnost narašča. Dielektrična konstanta določena pri 2 MHz se v raztopinah saharidov praviloma z naraščajočo koncentracijo zmanjšuje, izjema so raztopine inulina, oligofruktoze in maltodekstrina. Specifična električna prevodnost se z naraščajočo koncentracijo povečuje pri raztopinah oligosaharidov, pri raztopinah glukoze in fruktoze pa zmanjšuje.

Keywords

fizikalna kemija;fizikalne lastnosti;električne lastnosti;specifična električna prevodnost;dielektrične lastnosti;dielektrična konstanta;faktor dielektričnih izgub;ogljikovi hidrati;monosaharidi;dekstroza;glukoza;fruktoza;polisaharidi;inulin;vodne raztopine ogljikovih hidratov;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [Š. Gubenšek]
UDC: 544.03:537.226.1/.3:577.114.3/.7
COBISS: 4772216 Link will open in a new window
Views: 1938
Downloads: 649
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Other data

Secondary language: English
Secondary title: Dielectric properties of water solutions of some mono- and polysaccharides
Secondary abstract: In my master thesis we determined the dielectric properties of solutions of various saccharides. We analyzed the aqueous solution of glucose, fructose, inulin, dextrin, maltodextrin, oligofructose and glucose fructose syrup. The saccharides were characterized with determination of their reducing properties (dextrose equivalent), and the content of fructose in glucose fructose syrup. For determination of the dielectric constant in the range of frequencies between 20 kHz and 2 MHz we used a capacitive method and LCR meter. We were interested in the influence of type of the saccharide and the temperature on the dielectric properties of solutions with different concentration. The dielectric constant of polysaccharides and the dielectric loss factor decreased with increasing frequency; the dielectric constant of the monosaccharides solutions was independent of frequency. The dielectric constant of saccharides at 2 MHz decreased with increasing temperature, while the electrical conductivity increased. The dielectric constant at 2 MHz in solutions of saccharides decreased with increasing concentration, except for the solution of inulin, oligofructose and maltodextrin. The specific electrical conductivity increased with increasing concentration for solutions of oligosaccharides and decreased in solution of glucose and fructose.
Secondary keywords: physical chemistry;physical properties;electrical properties;specific electrical conductivity;dielectric properties;dielectric constant;dielectric loss factor of carbohydrates;monosaccharides;dextrose;glucose;fructose;polysaccharides;inulin;aqueous solution of carbohydrate;
Type (COBISS): Master's thesis/paper
Study programme: 0
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: XIII, 69 f., [5] f. pril.
ID: 9601251