Ekstrakcija bioaktivnih tvari iz vinskog taloga pomoću visokog tlaka

master's thesis

• Title (english): Extraction of bioactive compounds in wine lees using high hydrostatic pressure
• Author: Sara Lipovac
• Mentor: Damir Ježek (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Process Engineering); (Laboratory for Unit Operations); Zagreb
• Defense date and country: 2014-09-30, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U ovom istraživanju se udio bioaktivnih tvari određivao u vinskom talogu. Vinski talog je podvrgnut sušenju 48 h na temperaturi od 60 ◦C. Suhi talog je samljeven i stavljen u plastične bočice u eksikatoru do uporabe. Istraživanje je pokazalo da gustoća, veličina čestice i boja ne utječu direktno na stupanj ekstrakcije. Pokazalo se da je boja povezana sa udjelom fenola kada se uspoređuju mjerenja ukupnih fenila i antioksidanata. Uzorci s najmanjom L* vrijednosti su imali najveći udio fenolnih spojeva. Najveća koncentracija ukupnih fenola je bila pri primijenjenom tlaku od 400 MPa, međutim pokazala se statistički značajna razlika već kod tlaka od 100 MPa u odnosu na klasičnu ekstrakciju. Stoga, optimalan tlak za ekstrakciju fenolnih spojeva bi bio 100 MPa. Isto se može zaključiti za koncentraciju ukupnih antocijana. Tijekom obrade vinskog taloga napravljena su dva pokusa, jedan u trajanju od pet minuta, a drugi u trajanju od 15 minuta. U oba pokusa nije bilo značajne razlike kod koncentracije ukupnih antocijana, no bila je nešto veća kod koncentracije ukupnih fenola te se može zaključiti da je optimalno trajanje obrade pet minuta. Nadalje, pokazalo se da je etanol puno bolje otapalo od vode, što je i bilo očekivano. Što se tiće ispitivanih uzoraka, talog Jazbine je imao najveći udio bioaktivnih komponenata, zatim Vranac te na zadnjem mjestu talog Blatine.

Abstract (english)

In this study the phenolic content of wine lees was examined. Wine lees were dried for 48h at a temperature of 60 ◦C to prevent phenol degradation. The dried wine lees were milled and stored in plastic bottles within an exicator. The study showed that density, particle size and color do not influence the degree of extraction directly. Color is linked to phenol concentration when comparing the total phenol and total antioxidant content. Samples with the lowest L* value had the highest concentration of phenols. High pressure treatment at 400 MPa yielded the highest concentration of total phenols. However, total phenol yield was statistically significant at 100 MPa and could be considered the optimal pressure for phenol extraction. The same conclusion can be made for total anthocyanin concentrations. Two experiments were made with the duration of treatment five minutes in one experiment and fifteen minutes in the second. There was no statistically significant difference in total anthocyanin concentration during the two experiments, therefore it can be concluded that treatment of five minutes is the optimal amount of treatment. Even though total phenol concentrations were higher during fifteen minute treatments, treatment of five minutes is considered optimal, as well. Lastly, ethanol showed a higher extraction rate compared to water. Of the three studied samples, Jazbina had the highest content of bioactive compounds followed by Vranac and, lastly, Blatina.

• Keywords: visoki hidrostatski tlak; vinski talog; fenoli; HPLC
• Keywords (english): high hydrostatic pressure; wine lees; phenols; HPLC
• Language: croatian
• URN:NBN: urn:nbn:hr:159:606385
• Study programme: Title: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka prehrambenog inženjerstva (magistar/magistra inženjer/inženjerka prehrambenog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-02 12:28:47