Utjecaj ciklodekstrina na bioraspoloživost hidroksitirosola, tirosola i oleuropeina iz ekstrakta komine masline

master's thesis

• Title (english): The effect of cyclodextrins on bioavailability of hydroxytirosol, thyrosol and oleuropein from olive pomace extracts
• Author: Martina Horvat
• Mentor: Dubravka Vitali Čepo (mentor)
• Committee member: Dubravka Vitali Čepo (predsjednik povjerenstva)
• Committee member: Mario Jug (član povjerenstva)
• Committee member: Lovorka Vujić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of food chemistry); Zagreb
• Defense date and country: 2019-06-13, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Komina masline je ostatak koji u velikim količinama ostaje nakon proizvodnje maslinovog ulja. Obiluje
polifenolima koji pokazuju antioksidativna svojstva. Cilj ovog rada bio je istražiti stabilnost i
bioraspoloživost specifičnih biološki aktivnih spojeva komine tijekom in vitro simulacije gastrične i
intestinalne probave. Uzorci obuhvaćeni istraživanjem uključuju čisti (nativni) estrakt komine te ekstrakte
poboljšanih tehnoloških (organoleptičkih) svojstava pripremljenih korištenjem različitih vrsta
ciklodekstrina. Osim istraživanja gastrointestinalne stabilnosti, ispitivanjem permeabilnosti dijalizijskim
membranama određena je količina bioraspoložive frakcije polifenola u pojedinim uzorcima. Udio ukupne
količine biodostupnih i bioraspoloživih polifenola određen je Folin-Ciocalteu metodom, antioksidacijski
kapacitet TEAC metodom, a udio hidroksitirosola, tirosola i oleuropeina primjenom kromatografije
(HPLC). Hidroksitirosol je najzastupljeniji od karakterističnih fenola u ekstraktu komine masline (78,4 –
108,7 μg/100mg). Korištenjem ciklodekstrina u pripremi ekstrakata povećan je antioksidacijski potencijal,
udio ukupnih fenola te prinosi hidroksitirosola i oleuropeina. Količina ukupnih polifenola i antiradikalni
kapacitet uzoraka se tijekom in vitro probave povećavaju neovisno o prisustvu i vrsti ciklodekstrina (porast
od 157,3 – 189,9 mg GAE/100 g). Karakteristični fenoli komine masline su stabilni u gastrointestinalnom
sustavu osim oleuropeina koji se u intestinalnoj fazi u potpunosti razgrađuje. Prisutnost ciklodekstrina u
uzorku komine masline negativno utječe na dijalizabilnost biološki aktivnih spojeva (manja za 4,0% –
20,9%) . Potrebna su daljnja istraživanja na Caco-2 staničnim kulturama i in vivo istraživanja kako bi se
dobio bolji uvid u stabilnost i biodostupnost fenola masline.

Abstract (english)

Olive pomace is a by-product that remains in large quantities after olive oil production. It is rich in
polyphenols that show antioxidant properties. The aim of this research was to examine the stability and
bioavailability of specific biologically active compounds of olive pomace during the in vitro simulation of
gastric and intestinal digestion. Samples analysed in the frameworks of this study included native olive
pomace extract and extracts with improved tehnological (organoleptic) properties prepared using various
types of cyclodextrins. By examining permeability with dialysis membranes, the amount od bioavailable
fraction of polyphenols in each individual sample was determined. The share of the total amount of
bioaccessible and bioavailable polyphenols was determined by the Folin-Ciocalte method, the antioxidant
capacity by the TEAC method, and the share of hydroxytrosol, tirosol and oleuropein by chromatography
(HPLC). Hydroxytyrosol was the most abundant among the specific phenols of olive pomace (78,4 – 108,7
μg / 100mg). By using cyclodextrins for olive pomace extract preparation, the antioxidant potential, the
share of total phenols and the yields of hydroxytrosol and oleuropein increased. The amount of total
polyphenols and the antiradical capacity of the samples during in vitro digestion increased regardless of the
presence and type of cyclodextrin (157,3 – 189,9 mg GAE / 100g increase). Characteristic olive pomace
phenols were stable during the gastrointestinal digestion with the exception of oleuropein, that was
completely degraded during intestinal phase. The presence of cyclodextrins in the olive pomace extracts
negatively affected the dializability of biologically active compounds (reduction from 4,0% to 20,9%).
Further studies in Caco-2 cell model or in vivo studies are needed to obtain a better insight into the stability
and bioavailability of olive pomace phenols.

• Keywords: komina masline; gastrointestinalna stabilnost; biodostupnost; bioraspoloživost; tirosol; hidroksitirosol; oleuropein
• Keywords (english): olive pomace; gastrointestinal stability; bioavailability; bioaccessibility; tyrosol; hydroxytyrosol; oleuropein
• Language: croatian
• URN:NBN: urn:nbn:hr:163:226368
• Study programme: Title: Pharmacy; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra farmacije (magistar/magistra farmacije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-02-21 16:07:05