Izolacija steviol-glikozida iz biljke Stevia rebaudiana

master's thesis

• Title (english): Isolation steviol-glycosides from the plant Stevia rebaudiana
• Author: Željka Filipović
• Mentor: Branka Levaj (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; Zagreb
• Defense date and country: 2012-02-10, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Diplomski rad se bavi pojednostavljenjem proizvodnog procesa za razdvajanje i dobivanje sladila. Kako bi se uklonilo što više nečistoća iz uzorka, korišteni su procesi ekstrakcije, centrifugiranja, membranske filtracije, isparavanja i na kraju obrada etanolom. Obrada etanolom provodi se u svrhu taloženja s ciljem da se ukloni što više nečistoća, čime može doći do taloženja steviol-glikozida i time do promjena u njegovom udjelu u tekućoj fazi i talogu. Uspješnost uklanjanja nečistoća je povezana koncentracijom etanola kojom se provodi taloženje. Provedena istraživanja su pokazala da je 90 % koncentracija etanola optimalna. Međutim čini se da nakon dodatka etanola u većoj koncentraciji od 90 % u tekućoj fazi zaostane veća količina nečistoća i 50 % steviol-glikozida, dok se ostali ''čisti'' steviol-glikozid nalazi u talogu. Da bi se ta zapažanja mogla potvrditi potrebna su daljnja istraživanja.

Abstract (english)

This work deals with the simplification of the process procedure for the separation and recovery of steviol-glycosides (stevioside, rebaudioside A and rebaudioside C). In order to obtain the pure these sweeteners in the sample, following processes were used: extraction, centrifugation, membrane filtration, evaporation and at the end treatment with ethanol. Treatment with ethanol is carried out for precipitation of impurities, but it can lead to deposition of steviol-glycosides. In this work it was shown that the success of removal of impurities related to the concentrations of ethanol, which were used for precipitation. Optimal ethanol concentration for steviolglycosides precipitation was 90 %. It seems that after the addition of ethanol in higher concentrations than 90 % in the liquid phase left behind a large quantity of impurities and 50 % of steviol-glycosides, while the other ''clean'' steviol-glycosides are located in the sediment. To confirm these observations futher research are necessary.

• Keywords: Stevia rebaudiana; steviol-glikozid; steviozid; rebaudiozid A
• Keywords (english): Stevia rebaudiana; steviol-glycosides; stevioside; rebaudioside A
• Language: croatian
• URN:NBN: urn:nbn:hr:159:865874
• Study programme: Title: Food Safety Management; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka upravljanja sigurnošću hrane (magistar/magistra inženjer/inženjerka upravljanja sigurnošću hrane)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-09 11:20:52