Potencijal primjene proteina sirutke za poboljšanje inkapsulacijske učinkovitosti polifenola zelenog čaja

undergraduate thesis

• Title (english): The potential of using whey proteins for improving the encapsulation efficiency of green tea polyphenols
• Author: Danijela Suić
• 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: 2014-09-11, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

S obzirom na visok udjel polifenolnih spojeva i metilksantina, posebice kafeina u zelenom čaju, u ovom radu ispitana je ekstrakcijska učinkovitost ovih spojeva iz zelenog čaja kao model-sustava te njegova inkapsulacija u čestice različitih kombinacija alginata, proteina sirutke i kitozana. Usporedbom primjenjenih ekstrakcijskih postupaka, pokazalo se da je optimalni ekstrakcijski postupak ponovljena (dvostruka) konvencionalna ekstrakcija miješanjem na 80°C tijekom 15 minuta. Dobiveni ekstrakt sadržavao je 5 250 mg ekv. galne kiseline/L ekstrakta ukupnih polifenola te je inkapsuliran u čiste alginatne čestice, kombinaciju alginata s proteinima sirutke (8:2) te istu kombinaciju s kitozanskim omotačem. Dobivenim česticama ispitana su morfološka svojstva, veličina čestica, tekstura, inkapsulacijska učinkovitost te otpuštanje iz hidrogel i osušenih čestica. Rezultati su pokazali da je primjena proteina sirutke u kombinaciji s alginatom omogućila poboljšanje parametara inkapsulacije (veličina čestica, inkapsulacijska učinkovitost, produljenje otpuštanja) u odnosu na čiste alginatne čestice. Kao optimalan sustav pokazale su se alginatno-proteinske čestice s kitozanskim omotačem budući da su omogućile 89,2% inkapsulacije ukupnih polifenola te postepeno otpuštanje ovih spojeva u vodi i do 120 minuta.

Abstract (english)

Considering the high content of polyphenols and methylxanthines, especially caffeine in green tea, in this work the extraction efficiency of these compounds from green tea as a model system and its encapsulation in different combinations of alginate, chitosan and whey proteins was studied. By comparing the employed extraction procedures of green tea, it was established that repeated conventional extraction by stirring at 80 ° C for 15 minutes was the optimal extraction procedure. The obtained extract exhibited 5 250 mg eq. gallic acid/L of total polyphenols and was encapsulated in plain alginate particles, blend of alginate and whey proteins (8: 2) and in the same combination with chitosan coating. The morphological characteristics, particle size, texture, encapsulation efficiency and release from the obtained hydrogel and dried particles was examined. The results revealed that the use of whey proteins in combination with alginate ensures improvement of encapsulation parameters (particle size, encapsulation efficiency, release time prolongation) in relation to the plain alginate particles. Alginate-protein particles with chitosan coating was proved as the optimal delivery formulation of green tea bioactive compounds,since it exhibited 89.2% encapsulation efficiency of total polyphenols and sustained release of these compounds in water up to 120 minutes.

• Keywords: alginat; flavan-3-oli; inkapsulacija; polifenoli; proteini sirutke; zeleni čaj
• Keywords (english): alginat; flavan-3-ols; encapsulation; polyphenols; Whey proteins; green tea
• Language: croatian
• URN:NBN: urn:nbn:hr:159:622402
• Study programme: Title: Food Technology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka prehrambene tehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka prehrambene tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-04-26 13:33:25