Spektrofotometrijsko određivanje polifenola u etanolnim ekstraktima lovora (Laurus nobilis L.)

undergraduate thesis

• Title (english): Spectrophotometric determination of polyphenols from ethanol extracts of laurel (Laurus nobilis L.)
• Author: Angela Matanović
• Mentor: Antonela Ninčević Grassino (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Chemistry and Biochemistry); (Laboratory for Analytical Chemistry); Zagreb
• Defense date and country: 2017-09-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Polifenoli su sekundarni metaboliti biljaka vrlo raznolike strukture koja im među mnogobrojnim funkcijama, omogućava i antikorozijsku aktivnost. Antikorozijsko djelovanje polifenola temelji se na mehanizmu adsorbcije te tvorbi zaštitnih filmova na površini metala ili metalnih legura. Cilj ovog rada bio je odrediti optimalne uvjete ultrazvučne ekstrakcije polifenola iz suhih listova lovora, koji će se koristiti u daljnjim pripravama ekstrakata namijenjenih za antikorozijska ispitivanja. Na temelju dobivenih vrijednosti masenih udjela ukupnih fenola i flavonoida određenih UV/Vis spektrofotometrijom, među postavljenim uvjetima ultrazvučne ekstrakcije (vrijeme 3, 6 i 9 min, amplituda 60, 80 i 100 %, te 30 i 70 %, v/v etanol), vrijeme od 9 min, 100 %-tna amplituda i 70 %-tni etanol odabrani su kao optimalni parametri koji će se koristiti pri ekstrakciji polifenola kao ekološki prihvatljivih inhibitora korozije.

Abstract (english)

Polyphenols are secondary plant metabolites of very diverse structures, which among lot of functions, also provide anticorrosion activity. Anticorrosion action of polyphenols is based on adsorption mechanism with formation of protective films on metals and metal alloys surface. The aim of this work was determination of optimum ultrasonic extraction conditions of polyphenols from dry laurel leaves, which will be used in further preparation of extracts for monitoting of its anticorrosive activity. On the basis of obtained mass fraction values of total phenols and flavonoides, determined by UV/Vis spectrophotometry, among used ultrasound extraction conditions (time 3, 6 and 9 min, amplitude 60, 80 and 100 %, and 30 and 70 % ethanol), the time of 9 min, 100 % amplitude and 70 % ethanol are chosen as optimal parameters for extraction of polyphenols as a ecologically acceptable corrosion inhibitors.

• Keywords: antikorozijska aktivnost; ekstrakcija; lovor; polifenoli; ultrazvuk
• Keywords (english): anticorrosion activity; extraction; laurel; polyphenols; ultrasound
• Language: croatian
• URN:NBN: urn:nbn:hr:159:540775
• 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: Open access
• Created on: 2017-09-26 08:24:55