Primjena polifenola i pektina iz otpada hrane u zelenoj sintezi nanočestica selena

master's thesis

• Title (english): Use of polyphenols and pectins from food waste in green synthesis of selenium nanoparticles
• Author: Kristina Katelan
• Mentor: Dubravka Vitali Čepo (mentor)
• Committee member: Dubravka Vitali Čepo (predsjednik povjerenstva)
• Committee member: Živka Juričić (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: 2022-06-17, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Selen je esencijalni kemijski element za zdravlje živih organizama. U obliku nanočestica selen pokazuje veću biološku djelotvornost i manju toksičnost od anorganskog selenita te jednaku biološku učinkovitost, ali smanjenu toksičnost od selenometionina. Cilj ovog diplomskog rada bio je iskoristiti ekstrakte dobivene iz komine mandarine, rajčice i masline u biogenoj sintezi nanočestica selena. U ovom radu sintetizirane su nanočestice selena stabilizirane sirovim i pročišćenim pektinima dobivenim iz komine mandarine i rajčice, a u polovicu uzoraka dodan je ekstrakt komine masline kako bi se proučile mogućnosti dodatne funkcionalizacije sintetiziranih nanosustava u smislu poboljšanja antioksidativne aktivnosti. Dobiveni uzorci karakterizirani su kroz određivanje raspodjele veličine čestica, koncentracije i zeta potencijala (DLS metoda) te određivanjem reduktivne i antiradikalne sposobnosti (TEAC i FC metoda). Također, analizirana je i stabilnost nanosustava ponavljanjem mjerenja veličine čestica, koncentracije i zeta potencijala nakon 2, 5, 9, 20 i 30 dana od početka analize. Uzorci stabilizirani pektinima komine rajčice pokazali su manje vrijednosti veličine čestica te negativniji zeta potencijal u odnosu na uzorke stabilizirane pektinima komine madarine. Uzorci funkcionalizirani dodatkom ekstrakta komine masline pokazali su značajno veće vrijednosti antioksidacijskog potencijala (primjenom obje korištene metode) što pokazuje da je ekstrakt komine masline moćan prirodni antioksidans primjenjiv u biogenoj sintezi nanočestica selena. Buduća istraživanja trebala bi proučiti mogućnosti sinteze nanočestica selena manjih od 100 nm koje bi potencijalno pokazale bolje biološke učinke i veću stabilnost te istražiti biodostupnost i druge aspekte bioloških učinaka nastalih nanosustava.

Abstract (english)

Selenium is a chemical element essential for the health of living organisms. In the form of nanoparticles, selenium shows greater biological effectiveness and smaller toxicity than inorganic selenite, then also equal biological effectiveness, but reduced toxicity than selenomethionine. The objective of this graduate thesis was to use the extracts obtained from the pomace of tangerines, tomatoes and olives in biogenic synthesis of selenium nanoparticles. For the purpose of this thesis, synthetised selenium nanoparticles were stabilized using crude and purified pectins obtained from the pomace of tangerines and tomatoes, while in one half of the samples olive pomace extract was added in order to study the possibilities of additional functionalisation of the synthetised nanosystems in terms of improvement of antioxidative activity. The obtained samples were characterized through determining particle size distribution, concentration and zeta potential (DLS method), then through determining reductive and antiradical ability (TEAC and FC method). Also, nanosystem stability was analysed by repeating the measurements of particle size, concentration and zeta potential after 2, 5, 9, 20 and 30 days from the beginning of the analysis. The samples stabilized by tomato pomace pectins showed smaller particle size values and more negative zeta potential in relation to the samples stabilized by tangerine pomace pectins. The samples functionalized with the addition of olive pomace extract showed significantly greater values of antioxidative potential (using both applied methods) which indicates that olive pomace extract is a powerful natural antioxidant applicable in the biogenic synthesis of selenium nanoparticles. Future research activities should study the possibilities for synthetising selenium nanoparticles inferior to 100 nm, which would potentially show better biological effects and greater stability, but also explore bioavailability and other aspects of biological effects of the resulting nanosystems.

• Keywords: nanočestice selena; biootpad; komina mandarine; komina rajčice; komina masline; zeta potencijal; veličina čestica; antioksidacijski potencijal; stabilnost
• Keywords (english): selenium nanoparticles; food waste; tangerine pomace; tomato pomace; olive pomace; zeta potential; particle size; antioxidant potential; stability
• Language: croatian
• URN:NBN: urn:nbn:hr:163:280074
• 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: 2022-07-05 11:44:48