Utjecaj metoda sušenja na antioksidacijska svojstva biljnih ekstrakata

master's thesis

• Title (english): The effect of different drying techniques on the antioxidant capacity of herbal extracts
• Author: Ivana Špišić
• 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: 2011-03-30, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U novije vrijeme poraslo je zanimanje znanstvenika za ponovnim korištenjem ljekovitog bilja u svrhu prevencije bolesti ali i liječenja različitih tegoba zbog visokog udjela polifenola i drugih biološki aktivnih spojeva (flavonoida, askorbinske kiseline i biljnih pigmenata) koji posjeduju visoki antioksidacijski kapacitet. Radi duljeg i boljeg očuvanja bioaktivnog sastava biljaka koriste se razne metode sušenja koje više ili manje utječu na smanjenje udjela ukupnih fenola i antioksidacijskog kapaciteta. Cilj ovog istraživanja bio je odrediti udio ukupnih fenola u vodenim i 75%-tnim etanolnim ekstraktima sedam svježih biljaka i istih sušenih na tri različita načina: na zraku, liofilizacijom i mikrovalovima, kao i njihov antioksidacijski kapacitet. Udio ukupnih fenola određen je spektrofotometrijski, a antioksidacijski kapacitet u reakciji s ABTS reagensom (2,2'- azinobis(3-etilbenzotiazolin-6-sulfonskom kiselinom)). Među vodenim ekstraktima svježih biljaka najveći udio polifenola određen je u ekstraktu borača, a najniži u ekstraktu koprive. 75%-tni etanolni ekstrakti su imali niži udio ukupnih polifenola u odnosu na vodene. Ekstrakti biljaka sušenih mikrovalovima pokazuju najniži udio ukupnih fenola i najmanji antioksidacijski kapacitet.

Abstract (english)

In recent years, many scientists grew interest in usage of medicinal herbs to prevent diseases and as therapy for different sufferings because of their high part of total phenolics and some other biological active compounds such as flavons, ascorbic acid and herbal pigments which have a great antioxidant capacity. Different drying techniques, used to preserve herb material and their biological active compounds, effect on decrease of total phenolics and antioxidant activity. The purpose of this study was to determine total phenolics and antioxidant capacity of aquatic and ethanolic (75%) extracts of fresh and herbs dried with three different methods: air-, freeze- and microwave dried. Total phenolics were determined spectrofotometricaly and antioxidant capacity in reaction with ABTS reagent (2,2'-azinobis(3- etilbenzotiazolin-6-sulfonic acid)). Among aquatic extracts of fresh herbs, in the extract of borage was determined the highest part of total phenolics, and the lowest in extract of nettle. In ethanolic (75%) extracts were determined lower parts of total phenolics when comparing them to aquatic extracts. Extracts of microwave dried herbs show the lowest part of total phenolics and antioxidant capacity.

• Keywords: antioksidacijski kapacitet; fenoli; sušenje; ljekovito bilje; biljni ekstrakti; ABTS
• Keywords (english): antioxidant capacity; phenols; drying; medicinal herbs; herbal extracts; ABTS
• Language: croatian
• URN:NBN: urn:nbn:hr:159:136313
• Study programme: Title: Food Technology; specializations in: Food Engineering; Course: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo (diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-30 11:43:08