<p>Cilj ove doktorske disertacije je dobijanje višestrukih V<sub>1</sub>/U/V<sub>2</sub> emulzija kao nosača aktivnih materija u dvostepenom postupku, pri čemu se za drugi korak pripreme koristi tehnika membranskog emulgovanja (ME), na membrani od sinterovanog stakla implementiranoj u ćeliju sa mešanjem. Proces ME koristi se u svrhu unapređenja karakteristika formiranih emulzija, u smislu bolje kontrole veličine i raspodele veličina formiranih kapi, koje mogu da dovedu do razlika u stepenu inkapsulacije aktivnih materija u unutrašnjoj vodenoj fazi, u odnosu na proces u kome se za drugi korak pripreme emulzija koristi tehnika homogenizacije.<br />Kompletna optimizacija sastava V<sub>1</sub>/U emulzija, koja obuhvata određivanje koncentracije hidrofobnog emulgatora (PGPR), lipofobne materije (NaCl) i tikvinog ulja kao sekundarne aktivne komponente, rezultirala je formiranjem stabilnih nanoemulzija sa poboljšanim nutritivnim svojstvima. Nutritivno unapređeni emulzioni sistemi optimizovanog sastava korišćeni su za inkapsulaciju primarnih aktivnih komponenata (vodenog i etanolnog ekstrakata belog luka) u cilju zaštite bioaktivnih sastojaka i maskiranja neprijatnog mirisa i ukusa. Nakon definisanja sastava svih faza višestrukih emulzija, koje ukljuĉuje određivanje tipa hidrofilnog emulgatora i njegove koncentracije, kao i ispitivanja uticaja dodavanja osmotskog regulatora (glukoze) u spoljašnju vodenu fazu na stabilnost sistema i difuziju lipofoba, formirane su višestruke emulzije sa unetim aktivnim komponentama membranskim emulgovanjem u ćeliji sa mešanjem. Sistematiĉna karakterizacija membrane od sinter stakla kao ekonomski opravdanog membranskog materijala, dala je mogućnost njegove primene u procesu. Detaljno ispitivanje uticaja procesnih parametara (transmembranskog pritiska i brzine mešanja) i višekriterijumska optimizacija procesa ME, dovela su do formiranja višestrukih emulzija sa užom raspodelom veličina kapi, koja je indirektno uticala i na poboljšanje zadržavanja inkapsuliranog materijala u unutrašnjosti emulzija tokom vremena, u odnosu na emulzije pripremljene u postupku homogenizacije.</p> / <p style="text-align: justify;">The aim of this doctoral thesis was to prepare multiple W/O/W emulsions with encapsulated active substances in both phases, by a two-step process, where the stirred cell membrane emulsification (ME) process, with a sintered glass filter disk as a membrane, was used as the second step, instead of conventional process (homogenization). The ME process was employed in order to improve the characteristics of the formed emulsions, in terms of better control of the size and droplet size distribution, that can change the encapsulation degree of active ingredients in the internal aqueous phase.<br />The complete optimization of W/O emulsion composition, which includes determination of optimal contents of a hydrophobic emulsifier (PGPR), a lipophobic substance (NaCl) and pumpkin seed oil as an active component of the oil phase, resulted in the formation of stable nanoemulsions with improved nutritional properties. This nutritionally enhanced emulsion was used to encapsulate primary active ingredients (aqueous and ethanol garlic extract), in order to protect instable bioactive compounds of the extracts and mask the unpleasant smell and taste. After defining the composition of all phases of multiple emulsions, which includes determination of a suitable hydrophilic emulsifier and its optimal content, as well as examining the effect of addition of an osmotic regulator (glucose) in the external aqueous phase on the emulsion stability and lipophobe diffusion, multiple emulsions with encapsulated active components were formed by membrane emulsification in the stirred cell. The complete characterization of the sintered glass as an economically favourable membrane material, gave the possibility of its application in the process. Investigation of the influence of process parameters (transmembrane pressure and impeller rotation speed) and multiobjective optimization of ME, led to the formation of the multiple emulsions with a narrow droplet size distribution, which had improved retention of encapsulated material in the internal water phase over time, relative to the emulsions prepared by the homogenization process.</p>
| Identifer | oai:union.ndltd.org:uns.ac.rs/oai:CRISUNS:(BISIS)107583 |
| Date | 27 September 2018 |
| Creators | Bajac Jelena |
| Contributors | Nikolovski Branislava, Petrović Lidija, Milašinović Nikola |
| Publisher | Univerzitet u Novom Sadu, Tehnološki fakultet Novi Sad, University of Novi Sad, Faculty of Technology at Novi Sad |
| Source Sets | University of Novi Sad |
| Language | Serbian |
| Detected Language | Unknown |
| Type | PhD thesis |
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