magistrsko delo
Sandra Kopše (Avtor), Maša Knez Hrnčič (Mentor), Katja Andrina Kravanja (Komentor)

Povzetek

V magistrskem delu je predstavljen postopek formulacije ekstraktov iz lupine granatnega jabolka v biorazgradljive polimerne nosilce. Postopek je sestavljen iz treh faz: faze ekstrakcije, faze analiziranja pridobljenih ekstraktov in faze enkapsulacije ekstraktov v organogel ter nadaljnjo in vitro sproščanje aktivnih učinkovin v simuliranih človeških tekočinah. Z uporabo treh različnih ekstrakcijskih metod – hladna maceracija, ultrazvočna ekstrakcija in superkritična (SC) ekstrakcija in dveh različnih topil (čisti etanol in mešanica etanola in vode) smo skušali iz suhe lupine granatnega jabolka ekstrahirati čim več ciljnih fenolnih spojin, to je galne kisline in rutina. S kvalitativno in kvantitativno analizo smo prišli do zaključka, da je ekstrakt, pridobljen s SC ekstrakcijo in topilom mešanice etanol-voda, vseboval največji delež galne kisline (3.546,38 µg/g) in rutina (358,49 µg/g). S spektrofotometričnimi analiznimi metodami smo določili antioksidativno učinkovitost ekstraktov. Rezultati so pokazali, da so vsi ekstrakti vsebovali visok delež fenolnih spojin in dosegli visok % inhibicije – dobro antioksidativno delovanje. Protimikrobno delovanje ekstraktov smo preverjali tako pri gram negativnih kot pri gram pozitivnih bakterijah. Določili smo, da je minimalna inhibitorna koncentracija za gram negativne bakterije 4,69 mg/mL oz. 9,38 mg/mL. Za gram pozitivne bakterije pa 18,75 mg/mL. Ekstrakt, ki je vseboval najvišji delež ciljnih fenolnih spojin, smo nato vkomponirali v organogel in spremljali in vitro sproščanje fenolnih spojin v 0,1 M HCl. Med procesom sproščanja smo periodično izvajali vzorčenje. Po 24 urah smo vzorce analizirali s pomočjo tekočinske kromatografije in masne spektrometrije (LC/MS), z namenom, da bi ugotovili kolikšen delež fenolnih spojin smo vkomponirali v izbran organogel, kako hitro so se fenolne spojine sproščale med procesom in kolikšen delež fenolnih spojin se je sprostil. Rezultati so pokazali, da izbran organogel (osnova sončnično olje) ni bil najbolj primeren za enkapsulacijo fenolih spojin in na njihovo sproščanje. Ugotovili smo, da je bila vsebnost fenolnih spojin v organogelu nizka (nizek % vključitve ekstrakta v organogel). Sproščanje pa je potekalo hitro (v prvih dveh urah se je izločilo največ fenolnih spojin), kar bi pomenilo, da bi antioksidativno in protimikrobno delovanje v telesu potekalo kratek čas.

Ključne besede

granatno jabolko;galna kislina;antioksidativni učinek;in vitro sproščanje;organogel;magistrske naloge;

Podatki

Jezik: Slovenski jezik
Leto izida:
Tipologija: 2.09 - Magistrsko delo
Organizacija: UM FKKT - Fakulteta za kemijo in kemijsko tehnologijo
Založnik: [S. Kopše]
UDK: 66.061.3:582.772.1(043.2)
COBISS: 133158915 Povezava se bo odprla v novem oknu
Št. ogledov: 71
Št. prenosov: 23
Ocena: 0 (0 glasov)
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Ostali podatki

Sekundarni jezik: Angleški jezik
Sekundarni naslov: Formulation of extracts of pomegranate (punica granatum, l.) into biodegradable polymer matrices
Sekundarni povzetek: The master thesis presents the formulation of pomegranate peel extracts into biodegradable polymer matrices. The process consists of three phases: extraction, extract analysis and encapsulation of the extracts in organogel, combined with determination of in vitro release of the active compounds in simulated body fluids. Using three different extraction methods, namely cold maceration, ultrasonic extraction, and supercritical extraction, and two different solvents (pure ethanol and a mixture of ethanol and water), we aimed to extract as many target phenolic compounds as possible (gallic acid and rutin) from dry pomegranate peels. With further spectrophotometric analysis, we concluded that the extract obtained by the SC extraction and the ethanol-water mixture contained the highest amount of gallic acid (3,546.38 µg/g) and rutin (358.49 µg/g). Antioxidant efficiency of the extracts was determined by using spectrophotometric analysis methods. The results showed that all extracts contained a high proportion of phenolic compounds and achieved a high % of inhibition (that means good antioxidant activity). The antimicrobial activity of the extracts was tested against gram-negative and gram-positive bacteria. The minimum inhibitory concentration for gram-negative bacteria was determined as 4.69 mg/mL and 9.38 mg/mL and for gram-positive bacteria 18,75 mg/mL. The extract which contained the highest proportion of target phenolic compounds was then used for encapsulation in organogel. This was followed by in vitro release testing in 0.1 M HCl simulating gastric fluid. The tests were performed over 24 hours with the periodical sampling and analysed by liquid chromaptograpy and mass spectormetry (LC/MS). The aim was to evaluate the amount of phenolic compounds incorporated into the selected organogel, to determine the release kinetics of phenolic compounds released during the process, and to determine the concentration of phenolic compounds released. The results showed that the selected organogel (prepared from sunflower oil) was not the most suitable for the encapsulation of phenolic compounds and their release. We found that the content of phenolic compounds in the organogel was relatively low due to the low % incorporation of the extract into the organogel. However, the release was rapid (most phenolic compounds were released in the first two hours of the process), which could mean that the antioxidant and antimicrobial effects would occur in the body shortly after ingestion.
Sekundarne ključne besede: pomegranate;gallic acid;antioxidant effect;in vitro release;organogel;
Vrsta dela (COBISS): Magistrsko delo/naloga
Komentar na gradivo: Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Strani: 1 spletni vir (1 datoteka PDF (XI, 52 f.))
ID: 16713007