Utjecaj temperature skladištenja na polifenolni sastav stolnog grožđa

professional thesis

• Title (english): Effect of storage temeperature on the polyphenolic composition of table grapes
• Author: Hrvoje Šimičić
• Mentor: Višnja Katalinić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; Zagreb
• Defense date and country: 2011-11, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Istražen je utjecaj hladnog skladištenja na fenolni sastav i antioksidacijsku aktivnost ekstrakta pokožica bobica stolnog grožđa Vitoria i Black magic cv. Fenolni sastav ekstrakata određen je UV-VIS i HPLC metodama. Antioksidacijska aktivnost određena je primjenom FRAP, DPPH i ABTS metoda. Rezultati istraživanja ukazuju na značajne razlike fenolnog sastava i antioksidacijskih svojstava ekstrakata pokožica grožđa sorti Vittoria i Black magic. Pokožice grožđa Black magic cv. bile su višestruko bogatije ukupnim fenolima i imale su izuzetno dobru antioksidacijsku aktivnost. HPLC analiza potvrđuje razlike u polifenolnom fingerprintu. Ekstrakti pokožica bijele sorte Vittoria bili su bogatiji flavonolima, posebno kvercetin-4-glukozidom. U ekstraktima pokožica crne sorte Black magic dominirali su antocijani i flavan-3-oli. Dokazana je prisutnost stilbena. Grožđe Vittoria i Black magic skladišteno je u rashladnim komorama pri 4 ˚C (T1) i 12 ˚C (T2). Rezultati istraživanja ukazuju na lagani trend pada koncentracije pojedinih fenolnih spojeva s dobrim antioksidacijskim učinkom, tijekom čuvanja u hladnjačama, naročito tijekom prvih tjedana skladištenja. Nije potvrđena značajna korelacija između antioksidacijske snage i udjela pojedinih fenolnih spojeva u ekstraktima.

Abstract (english)

The effect of cold storage on the phenolic composition and antioxidant properties of grape skin extracts of table grapes cultivars Vitoria and Black magic cv. was researched. Phenolic composition of grape skin extracts was analysed using UV-VIS and HPLC methods. Antioxidant activity was determined using FRAP, DPPH and ABTS methods. The results of this research confirmed significant differences in phenolic composition and antioxidant properties between the extracts prepared from Vittoria and the ones coming from Black magic cv. grape. Black magic cv. grape skin extracts were several times richer in total phenols and showed exceptionally good antioxidant activity. HPLC analysis confirmed differences in grape skin extracts polyphenolic fingerprints. Vittoria grape skin extracts were richer in flavonols, especially querectin-4-glucoside. Anthocyanins and flavan-3-ols dominated in the grape skin extracts of red table grapes Black magic. The presence of stilbenes was also confirmed. Table grapes Vittoria and Black magic were stored in low temperature conditions, at 4 ˚C (T1) and 12 ˚C (T2). According to the obtained results, a slight decrease in concentration of some phenolic compounds with good antioxidant properties was noticed during the cold storage, especially during the first week. A significant correlation between antioxidant properties and the content of some phenolic compound in grape skin extracts was not confirmed.

• Keywords: stolno grožđe; ekstrakti pokožica; polifenoli; antioksidacijska aktivnost; hladno skladištenje
• Keywords (english): table grapes; skin extracts; polyphenols; antioxidant activity; cold storage
• Language: croatian
• URN:NBN: urn:nbn:hr:159:409820
• Study programme: Title: Postgraduate Specialist Studies in Food Quality and Safety; Study programme type: university; Study level: postgraduate specialist; Academic / professional title: sveučilišni/a specijalist/specijalistica kvalitete i sigurnosti hrane (sveučilišni/a specijalist/specijalistica kvalitete i sigurnosti hrane)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2018-05-15 13:35:24