Antioksidacijski potencijal različito pripremljenih ekstrakata majčine dušice

undergraduate thesis

• Title (english): Antioxidant capacity of differently prepared thyme extracts
• Author: Doroteja Dević
• 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: 2014-07-10, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Nutrition

Abstract

Majčina dušica (T. serpyllum) je ljekovita biljka koja raste na suhim i sunčanim površinama. Brojni se pozitivni zdravstveni učinci vezuju uz tu biljku, ponajviše zbog izraženog antoksidacijskog potencijala polifenolih spojeva koje sadrži. Cilj ovoga rada bio je odrediti antioksidacijski potencijal ekstrakata majčine dušice pripremljenih kombinacijom različitih temperatura i vremena ekstrakcije te uporabom ultrazvučne kupelji. Spektrofotometrijskim metodama određen je udjel ukupnih polifenola, flavonoida, proantocijanidina, hidroksicimetnih kiselina i tanina. Antioksidacijski potencijal ekstrakata određen je reakcijom s radikal - kationom 2, 2' - azinobis (3 - etilbenzotiazolin - 6 - sulfonskom kiselinom) (ABTS metoda) i reakcijom s 1, 1 - difenil - 2 - pikrilhidrazil radikalom (DPPH metoda). Polifenolni sastav ekstrakata određen je visokodjelotvornom tekućinskom kromatografijom (HPLC - PDA). Među ispitivanim ekstrakcijskim postupcima, najučinkovitijim se pokazala klasična ekstrakcija majčine dušice vodom temperature 80°C tijekom 30 minuta koja je rezultirala ekstraktom s najvišim udjelom ukupnih polifenolnih spojeva te najvišim antioksidacijskim kapacitetom. U usporedbi s fiziološkom otopinom, destilirana voda pokazala se kao bolje otapalo za ekstrakciju polifenolnih spojeva.

Abstract (english)

Thyme (T. serpyllum) is a medicinal plant growing in dried and sunny areas. A great number of positive health effects are associated with this plant, mainly due to the presence of polyphenols which possess strong antioxidant potential. The aim of this study was to determine the antioxidant potential of thyme extracts prepared by combining different temperature, time of extraction and the use of an ultrasonic bath. The content of total polyphenols, flavonoids, proanthocyanidins, hydroxycinnamic acid and tannins was determined by spectrophotometric methods. Antioxidant potential of the extracts was determined by reaction with a radical - cation 2, 2' - azinobis (3 - ethylbenzothiazoline - 6 - sulfonic acid) (ABTS method) and reaction with 1, 1 - diphenyl - 2 - picrylhydrazyl radical (DPPH method). Polyphenolic composition of the extracts was also determined by high performance liquid chromatography (HPLC - PDA). Among studied extraction methods, classical procedure of thyme using water at 80 °C during 30 minutes was the most effective. The extract obtained using this procedure had the highest content of polyphenolic compounds and had the highest antioxidant capacity. Compared with physiological solution, distilled water proved to be a better solvent for the extraction of polyphenolic compounds from thyme.

• Keywords: antioksidacijski potencijal; ekstrakcija; majčina dušica; polifenoli
• Keywords (english): antioxidant capacity; extraction; thyme; polyphenols
• Language: croatian
• URN:NBN: urn:nbn:hr:159:494722
• Study programme: Title: Nutrition; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) nutricionizma (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) nutricionizma)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-04-26 11:22:35