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Title:Meritve osmolarnosti izotoničnih napitkov za hidracijo telesa pri športni aktivnosti : magistrsko delo
Authors:ID Skarlovnik, Tjaša (Author)
ID Bren, Urban (Mentor) More about this mentor... New window
ID Hostnik, Gregor (Comentor)
ID Lamut, Andraž (Comentor)
Files:.pdf MAG_Skarlovnik_Tjasa_2023.pdf (3,68 MB)
MD5: 568248F4A14C754EF828E18643C0D441
 
Language:Slovenian
Work type:Master's thesis/paper
Typology:2.09 - Master's Thesis
Organization:FKKT - Faculty of Chemistry and Chemical Engineering
Abstract:V magistrskem delu smo izmerili osmolalnosti in poskušali izmeriti toničnosti izotoničnih napitkov, ki jih je mogoče kupiti na slovenskem tržišču. Z osmometrom smo izmerili osmolalnosti vseh izotonikov, pri čemer smo ugotovili, da osmolalnost večine izotonikov sodi v območje med 270 in 330 mOsm/kg, ki ga EFSA predpisuje za izotonične napitke. Nadalje smo pripravili standardne raztopine natrijevega klorida različnih osmolalnosti, ki smo jih izpostavili rdečim krvničkam, da smo lahko s pomočjo opazovanja sipanja in absorpcije svetlobe opazovali vpliv raztopin različnih osmolalnosti na volumen in obliko celic. S tem smo naredili umeritveno krivuljo in določili spodnjo mejo izotoničnega območja. Ker je bila na zgornji meji razlika med raztopinami zelo majhna, smo za razlikovanje med raztopinami različne toničnosti v tem območju uporabili mikroskop z multimodalnim čitalcem, s katerim smo opazovali delež ježkov v posamezni raztopini ob času 20 in 60 minut po vstavitvi celic v raztopino. Delež ježkov je do raztopine z osmolalnostjo 300 mOsm/kg zanemarljivo majhen, nato se opazno poveča. V okviru proučevanja izotonikov smo najprej pomerili njihove UV/VIS spektre, da smo lahko opazovali, v katerem delu absorpcijskega spektra lahko zaznamo sipanje svetlobe. Nato smo izotonikom dodali še rdeče krvne celice in pomerili spektre, iz katerih smo s primerjavo z umeritveno krivuljo poskusili določiti toničnosti raztopin. Na prvi pogled je videti, da ima večina izotonikov manjšo toničnost, kot jo imajo standardne raztopine natrijevega klorida primerljive osmolalnosti. Vendar pa meritve otežujejo nizke vrednosti pH izotonikov, ki vplivajo na morfologijo rdečih krvničk. Da bi videli, kako je membrana rdečih krvničk prepustna za sladkorje, smo tudi preverili, kakšna je toničnost raztopin sladkorjev znane osmolalnosti. Vidimo lahko, da so membrane rdečih krvničk prepustne za določene saharide. To pomeni, da izotonični napitki, kljub ustrezni osmolalnosti, pogosto niso izotonični, saj je koncentracija sladkorjev v njih razmeroma visoka.
Keywords:osmolalnost, toničnost, hidracija, izotonični napitki, eritrociti
Place of publishing:Maribor
Place of performance:Maribor
Publisher:[T. Skarlovnik]
Year of publishing:2023
Number of pages:1 spletni vir (1 datoteka PDF (X, 74 f.))
PID:20.500.12556/DKUM-84448 New window
UDC:544.352.4(043.2)
COBISS.SI-ID:163554051 New window
Publication date in DKUM:26.07.2023
Views:588
Downloads:91
Metadata:XML DC-XML DC-RDF
Categories:KTFMB - FKKT
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Licences

License:CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
Link:http://creativecommons.org/licenses/by-nc-nd/4.0/
Description:The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.
Licensing start date:08.06.2023

Secondary language

Language:English
Title:Osmolarity measurements of isotonic drinks for body hydration during sports activity
Abstract:In this Master thesis, we measured the osmolarity and tried to measure the tonicity of isotonic drinks, that can be bought in Slovenian market. We measured the osmolality of all isotonic drinks with an osmometer and found, that the osmolality of most of them is in the range between 270 and 330 mOsm/kg, which are the limits that EFSA prescribes for isotonic drinks. Moreover, we prepared standard solutions of sodium chloride of different osmolality. We exposed red blood cells to these solutions to observe the influence of the osmolality on the volume and shape of the cells, by observing the scattering and absorption of light. We defined a calibration curve and determined the lower limit of the isotonic range. Since the difference between the solutions at the upper limit of isotonic range was small, we used a microscope with a multimodal reader to distinguish between the solutions of different tonicity in this area. Tonicity was observed by the proportion of crenations in each solution at 20 and 60 minutes after being exposed to the solution. The proportion of crenations is very small as to a solution with an osmolality of 300 mOsm/kg, after which it noticeably increases. At the beginning of studying isotonic drinks, we measured the spectra of these solutions to determine in which part of the absorption spectrum the light scattering can be observed. Then we added red blood cells to the isotonic drinks and measured the spectra, from which we tried to determine the tonicity of the solutions by comparing their measurements to the calibration curve. At first it seemed that most of isotonic drinks have a lower tonicity than standard sodium chloride solutions of comparable osmolality. However, the measurements were further complicated by the low pH values of isotonic drinks, which affects red blood cell morphology. We also tried to determine, how the red blood cell membrane is permeable to different sugars by measuring the tonicity of sugar solutions of known osmolality. We observed that the membranes of red blood cells are permeable to some saccharides. This means that isotonic drinks, despite the appropriate osmolality, are often not isotonic, as the concentration of sugars in them is relatively high.
Keywords:osmolality, tonicity, hydration, isotonic drinks, red blood cells


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