Određivanje različitih skupina fenolnih spojeva i antioksidacijskog kapaciteta u borovnicama (Vaccinium corymbosum L.)

master's thesis

• Title (english): Determination of different groups of fenolic compounds and antioxidant in blueberries (Vaccinium corymbosum L.)
• Author: Ana Brala
• Mentor: Verica Dragović-Uzelac (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Technology of Fruits and Vegetables Preservation and Processing); Zagreb
• Defense date and country: 2008-02-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Ukupni antocijani, ukupni fenoli, flavonoidi, flavan-3-oli i hidrolizirani tanini četiriju sorti borovnice kao i njihov antioksidacijski kapacitet praćen je tijekom sukcesivnog perioda berbe (tri termina). Antocijani su određeni metodom izbjeljivanja bisulfitom, dok su ukupni fenoli i hidrolizirani tanini određivani kolornom reakcijom sa Folin­Ciocalteu reagensom. Flavan-3-oli određivani su sa vanilinom te flavonoidi sa aluminijevim kloridom. Ukupni antioksidacijski kapacitet borovnice određivan je trima metodama׃ uporabom 2,2'-azinobis(3-etilbenzotiazolin-6-sulfonska kiselina) radikala (ABTS), redukcijom željezovog iona (FRAP) te uporabom 2,2-difenil-1-pikrilhidrazil (DPPH) radikala. Količine svih istraživanih skupina fenolnih spojeva nisu se ujednačeno mijenjale tijekom sukcesivnog perioda berbe. Antocijani su u najvećoj količini određeni u sorti Sierra u prvom i drugom periodu berbe. Najveće količine ukupnih fenola određene su u sortama Sierra i Elliot u prvom periodu berbe. U ukupnoj količini fenolnih spojeva prevladavali su spojevi iz skupine flavonoida i to u značajnim količinama. Flavan-3-oli su u najvećoj količini određeni u sorti Sierra u prvom periodu berbe, a hidrolizirani tanini u sorti Duke u prvom periodu berbe. U svim istraživanim sortama tijekom sukcesivnog perioda berbe određen je visok antioksidacijski kapacitet. Između svih skupina fenolnih spojeva i antioksidacijskog kapaciteta određeni su visoki koeficijenti korelacije izuzev s hidroliziranim taninima.

Abstract (english)

The total anthocyanins, total phenolics, flavonoids, flavan-3-ols and hydrolyzed tannins of four blueberry cultivars (Vaccinium corymbosum L.) as well as the corresponding antioxidant capacity were investigated during successive period of harvesting (three period). The total anthocyanin content was determined by bisulphate bleaching method, while the quantities of total phenolics and hydrolyzed tannins were determined by using Folin-Ciocalteu colorimetric method. Total flavan-3-ols were determined by using characteristic reaction with vanillin and flavonoids by using reaction with aluminum chloride. Total antioxidant capacity of blueberry fruits was determined by using three methods: 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation assay (ABTS), ferric ion reducing antioxidant power assay (FRAP), 2,2-diphenil-1-picrylhydrazyl radical scavenging capacity assay (DPPH). The amounts of all investigated group of polyphenols were not changed uniformly during successive period of harvesting. The higher amounts of anthocyanins in cultivar Sierra at 1st and 2nd harvesting period were observed, whereas the highest amounts of total phenols in cultivar Sierra and Elliot in 1st harvesting period were determined. The predominant group of phenolic compounds in all investigated cultivars at all harvesting period were flavonoids. The highest amount of flavan-3-ols was determined in cultivar Sierra and hydrolyzed tannins in cultivar Duke in 1st harvesting period. Total antioxidant capacity was very high in all investigated cultivar during successive period of harvesting. High correlation coeficients were observed between all investigated group of phenolics (excluded hydrolyzed tannins ) and antioxidant capacity.

• Keywords: antioksidacijski kapacitet; antocijani; ukupni fenoli; flavonoidi; flavan-3-oli; hidrolizirani tanini; borovnica
• Keywords (english): antioxidant capacity; total anthocyanins; total phenolic; total flavonoids; flavan-3-ols; hydrolyzed tannins; blueberry
• Language: croatian
• URN:NBN: urn:nbn:hr:159:005017
• 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: 2017-09-04 11:42:19