Trava iva (Teucrium montanum L.) – ekstrakcija bioaktivnih spojeva, inkapsulacija liposomima i formulacija funkcionalnih napitaka

master's thesis

• Title (english): Mountain germander (Teucrium montanum L.) – extraction of bioactive compounds, encapsulation in liposomes and formulation of functional drinks
• Author: Kristina Vugrinec
• Mentor: Draženka Komes (mentor)
• Committee member: Ksenija Durgo (član povjerenstva)
• 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: 2020-09-24, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Iako biljni polifenoli posjeduju brojne biološke učinke, zbog niske stabilnosti i bioraspoloživosti njihova primjena u hrani je ograničena. Stoga posljednjih godina raste interes znanosti i prehrambene industrije za razvojem učinkovitih i pouzdanih tehnika ekstrakcije i inkapsulacije bioaktivnih spojeva. Cilj ovog rada bio je usporediti učinkovitost konvencionalnih tehnika ekstrakcije uključujući infuziju, dekokciju i maceraciju s inovativnim tehnikama primjenom visokog hidrostatskog tlaka, subkritične vode i mikrovalova u ekstrakciji polifenolnih spojeva trave ive (Teucrium montanum L.) nakon čega je polifenolima najbogatiji ekstrakt inkapsuliran liposomima u svrhu formuliranja funkcionalnih napitaka kave. Dobivenim ekstraktima određeni su prinos ekstrakcije, udjel ukupnih polifenola te antioksidacijski kapacitet ABTS i DPPH metodama. Inkapsulacija polifenolnog ekstrakta provedena je liposomima s različitim omjerom ekstrakta i fosfolipida, 1:5, 1:10 i 1:20. Formiranim česticama ispitane su fizikalno-kemijske karakteristike te inkapsulacijska i antioksidacijska učinkovitost. Liposomi najboljih svojstava obloženi su slojem pektina ili alginata te je istima obogaćen napitak kave i tijekom četiri tjedna praćen je profil otpuštanja pojedinih polifenola. Konvencionalnim tehnikama dobiveni su ekstrakti s višim ekstrakcijskim prinosima u odnosu na inovativne, pri čemu je infuzijom ekstrahirano najviše ukupnih polifenola (41,13 mg EGK gˉ¹ s. t. uzorka), od čega je čak 35,93 % činio ehinakozid. Liposomi pripremljeni s većim udjelom fosfolipida (1:20), pokazali su najviši stupanj inkapsulacijske učinkovitosti za oba najzastupljenija polifenolna spoja trave ive, ehinakozid (68,27 %) i verbaskozid (80,60 %). Isti sustav pokazao je niske vrijednosti TBARS testa što ukazuje na visoki antioksidacijski potencijal inkapsuliranih spojeva u inhibiciji lipidne peroksidacije. Oblaganjem liposoma polimerima pospješilo se zadržavanje polifenolnih spojeva unutar strukture liposoma, pri čemu su liposomi obloženi alginatom pokazali sporiji profil otpuštanja polifenolnih spojeva u kavu u vremenskom periodu od četiri tjedna u odnosu na liposome obložene pektinom.

Abstract (english)

Although plant polyphenols possess numerous biological activities, due to their low stability and bioavailability, their application in food is limited. Therefore, in recent years, the interest of science and the food industry in the development of efficient and reliable techniques of extraction and encapsulation of bioactive compounds has been growing. The aim of this study was to compare the efficiency of conventional extraction techniques including infusion, decoction and maceration with innovative techniques using high hydrostatic pressure, subcritical water and microwaves in the extraction of polyphenols of mountain germander (Teucrium montanum L.) after which the polyphenol-rich extract was encapsulated with liposomes for the purpose of formulating functional coffee drinks. Prepared extracts were characterised by the determination of extraction yield, the content of total polyphenols and the antioxidant capacity (ABTS and DPPH assays). Encapsulation of the polyphenolic extract was performed with liposomes with different ratio of extract to phospholipids, 1: 5, 1:10 and 1:20. The physicochemical characteristics as well as encapsulation and antioxidant efficiency of the formed liposomes were examined. Liposomes with the best properties were coated with a layer of pectin or alginate and added to the coffee drink after which the polyphenol release profile was monitored for a period of four weeks. Conventional techniques resulted in higher extraction yields compared to innovative ones, with the most total polyphenols being extracted by infusion (41.13 mg EGA gˉ¹ DW), of which 35.93% was echinacoside. Liposomes prepared with a higher proportion of phospholipid (1:20) showed the highest degree of encapsulation efficiency for predominant polyphenolic compounds of mountain germander, echinacoside (68.27%) and verbascoside (80.60%). The same system showed low TBARS test values indicating a high antioxidant potential of encapsulated compounds in inhibiting lipid peroxidation. Coating liposomes with polymers enhanced the retention of polyphenols within the liposome structure, where alginate-coated liposomes showed a slower release profile of polyphenols in coffee over a four-week period compared to pectin-coated liposomes.

• Keywords: ekstrakcija; funkcionalni napitci; liposomi; polifenolni spojevi; trava iva
• Keywords (english): extraction; functional drinks; liposomes; mountain germander; polyphenols
• Language: croatian
• URN:NBN: urn:nbn:hr:159:481075
• 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: Open access
• Created on: 2021-01-21 13:05:17