Utjecaj vrste nosača na učinkovitost inkapsulacije bioaktivnih spojeva zelene kave

undergraduate thesis

• Title (english): The effect of carrier system on encapsulation efficiency of bioactive compounds derived from green coffee
• Author: Andrea Radošević
• 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; Biotechnology

Abstract

Svrha ovog završnog rada bila je ekstrakcija polifenolnih spojeva i kafeina iz zelene kave te njihova inkapsulacija u pet različitih sustava nosača (2% alginat, alginatpektin, alginat-karagenan, alginat s kitozanskim omotačem i alginat s pektinskim omotačem). Ekstraktima zelene kave dobivenima variranjem različitih uvjeta ekstrakcije (temperatura, vrijeme ekstrakcije, ultrazvuk) određen je udjel polifenola i kafeina te antioksidacijski kapacitet primjenom spektrofotometrijskih metoda i tekućinske kromatografije visoke djelotvornosti (HPLC). Među ispitivanim ekstrakcijskim postupcima, najučinkovitijim se pokazala konvencionalna ekstrakcija miješanjem na 80°C tijekom 20 minuta, koja je rezultirala ekstraktom s najvećim udjelom polifenolnih spojeva, klorogenske kiseline i kafeina te je tako dobiven ekstrakt korišten za inkapsulaciju u različite sustave nosača. Česticama dobivenim inkapsulacijom ekstrakta zelene kave određene su morfološke karakteristike, veličina čestica te reološka svojstva, učinkovitost inkapsulacije polifenola te je praćeno otpuštanje polifenola iz čestica u vodi. Najbolju učinkovitost inkapsulacije polifenolnih spojeva (87.09%) te produljenje otpuštanja istih (20-30 minuta) pokazali su sustavi kombinirani od alginata i pektina.

Abstract (english)

The purpose of this final work was extraction of polyphenolic compounds and caffeine from green coffee beans and their encapsulation using five different carrier systems (2% alginate, alginate-pectin, alginate-carrageenan, alginate with chitosan coating and alginate with pectin coating). In the green coffee extracts, obtained by employing different extraction conditions (temperature, time, ultrasound), their polyphenolic and caffeine contents, as well as antioxidant capacity were determined, using spectrophotometric methods and high performance liquid chromatography (HPLC). Among the employed extraction procedures, the most effective extraction procedure was conventional extraction by stirring at 80°C for 20 minutes, resulting with an extract that exhibited the highest content of polyphenolic compounds, chlorogenic acid and caffeine and thus obtained green coffee extract was further encapsulated in different delivery systems. The formulated particles were characterized for their morphological characteristics, particle size and rheological properties of the carrier systems, as well as the encapsulation efficiency of polyphenols and their release kinetics in distilled water. The best encapsulation efficiency of polyphenolic compounds (87.09%) and a prolonged release of these compounds (up to 20-30 minutes) were determined in case of alginate combined with pectin.

• Keywords: antioksidacijski kapacitet; inkapsulacija; kafein; polifenoli; zelena kava
• Keywords (english): antioxidant capacity; encapsulation; caffeine; polyphenols; green coffee
• Language: croatian
• URN:NBN: urn:nbn:hr:159:756539
• 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: 2017-04-27 13:18:27