Kinetika difuzije polifenola i proteina tijekom inkapsulacije ekstrakta zelenog čaja

undergraduate thesis

• Title (english): The diffusion of polyphenols and proteins during green tea extract encapsulation
• Author: Petra Vidović
• Mentor: Draženka Komes (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Chemistry and Technology of Carbohydrates and Confectionery Products); Zagreb
• Defense date and country: 2015-07-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

U cilju povećanja učinkovitosti inkapsulacije polifenolnih spojeva zelenog čaja, u ovom radu ispitane su interakcije između polifenola i različitih proteina primjenjenih za inkapsulaciju. Za formiranje čestica korišten je alginat i pet vrsta proteina (proteini sirutke, goveđi serum albumin, kalcijev kazeinat, proteini konoplje, proteini soje), a kao tehnika inkapsulacije primijenjeno je ionsko geliranje uz formiranje dodatnog pektinskog i kitozanskog omotača, kako bi se smanjila poroznost i postiglo produljeno otpuštanje inkapsuliranih sastojaka. Čestice formulirane od alginata te goveđeg serum albumina (BSA) i proteina sirutke sadržavale su najveći udjel zadržanih proteina (do 95% od polaznog udjela), dok se kombinacija alginata s kalcijevim kazeinatom i proteinima sirutke pokazala najučinkovitijom za inkapsulaciju polifenola i flavan-3-ola, jer navedena kombinacija materijala omogućava zadržavanje najvećeg udjela ovih spojeva u formuliranim česticama (80%). Tijekom postupka formiranja čestica nije došlo do difuzije polifenola i flavan-3-ola u okolni medij, zbog izotoničnih uvjeta korištenih tijekom inkapsulacije, no, došlo je do difuzije i otpuštanja proteina iz hidrogel matriksa čestica, što je rezultiralo manjim udjelom proteina zadržanim u formuliranim česticama. Prema dobivenim rezultatima alginat u kombinaciji s goveđim serum albuminum i pektinskim omotačem najefikasnije zadržava polifenole zelenog čaja i proteine unutar čestice, što se može upotrijebiti za postizanje kontroliranog otpuštanja ovih funkcionalnih komponenti.

Abstract (english)

This paper investigates the possibility of employing specific protein-polyphenol interactions for encapsulation of polyphenols and flavan-3-ols from green tea extract. Alginate was used for the formation of the particles, along with several types of proteins (whey protein, bovine serum albumin, calcium caseinate, hemp proteins, soy proteins), while ionic gelling was applied as the encapsulation technique, with additional pectin or chitosan coating, in order to reduce the porosity and achieve sustained release of encapsulated ingredients. The formulated particles containing alginate and bovine serum albumin (BSA) or whey proteins exhibited the largest proportion of retained proteins (up to 95% of the initial content), while the combination of alginate with calcium caseinate or whey proteins was the most effective for encapsulation of polyphenols and flavan-3-ols, since that combination of materials enabled to retain the largest content of these compounds in the formulated particles (80%). During the formation of particles no diffusion of polyphenols and flavan-3-ol in the surrounding medium occured, due to the isotonic conditions held during encapsulation, however, significant diffusion and release of proteins from the hydrogel matrix particles occured, resulting in lower protein content retained in the formulated particles. The results suggest that alginate in combination with bovine serum albumin and pectin coating is the most effective for encapsulation of green tea polyphenols and proteins within the particles, which is useful in achieving controlled release of these functional components.

• Keywords: alginat; difuzija; hidrogel čestice; inkapsulacija; polifenoli; proteini
• Keywords (english): alginat; diffusion; encapsulation; hydrogel particles; proteins
• Language: croatian
• URN:NBN: urn:nbn:hr:159:973574
• Study programme: Title: Biotechnology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-04-25 11:25:36