Izolacija biološki aktivnih tvari iz komine grožđa sorte Merlot

undergraduate thesis

• Title (english): Isolation of biologically active substances from waste of grape Merlot
• Author: Marija Tratnik
• 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: 2016-06-09, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Nutrition

Abstract

Cilj ovog istraživanja bio je ispitati utjecaj vremena ekstrakcije na izolaciju ukupnih fenolnih spojeva, monomernih antocijana, polimernih proantocijanidina te na antioksidacijski kapacitet u sjemenkama i pokožici grožđa sorte Merlot izdvojenih iz komine nakon proizvodnje vina. Ekstrakcija je provedena uz primjenu 80%-tne vodene otopine metanola za sjemenke i 80%-tne vodene otopine metanola sa 1%-tnom mravljom kiselinom za pokožicu, kroz vrijeme ekstrakcije 30, 50 i 70 minuta. Ukupni fenoli određivani su spektrofotometrijski FolinCiocalteu metodom, monomerni antocijani spektrofotometrijskom pH diferencijalnom metodom, polimerni proantocijanidini vanilin metodom te antioksidacijski kapacitet FRAP metodom. Porast vremena trajanja ekstrakcije utjecao je na povećanje prinosa ukupnih fenola, antocijana i proantocijanidina, a sukladno tome i na povećanje antioksidacijskog kapaciteta. Sadržaj ukupnih fenola, monomernih antocijana i antioksidacijski kapacitet bili su u gotovo svim uzorcima najveći nakon 70 minuta, a polimernih proantocijanidina nakon 50 minuta ekstrakcije.

Abstract (english)

The aim of this study was to investigate the influence of extraction time to the isolation of total phenolic compounds, monomeric anthocyanins, polymeric proanthocyanidins and antioxidant capacity in the grape seeds and skin of grape variety Merlot, separated from the pomace after wine production. Extraction was made with the use of 80% aqueous methanol for the seeds and with 80% aqueous methanol containing 1% formic acid for the skin, through the extraction time of 30, 50 and 70 minutes. Total phenolic compounds were determined by spectrophotometric Folin-Ciocalteu method, monomeric anthocyanins by spectrophotometric pH differential method, polymeric proanthocyanidins by vanillin method and antioxidant capacity by FRAP method. Extraction duration time growth influenced yield increase of total phenols, anthocyanins, proanthocyanidins and accordingly, to increase of the antioxidant capacity. The amount of total phenolic compounds, monomeric anthocyanins and antioxidant capacity in almost all samples was the highest after 70 minutes and after 50 minutes for polymeric proanthocyanidins.

• Keywords: ekstrakcija potpomognuta ultrazvukom; sjemenke i pokožica grožđa; fenolni spojevi; antioksidacijski kapacitet
• Keywords (english): ultrasonic-assisted extraction; grape seeds and skin; phenolic compounds; antioxidant capacity
• Language: croatian
• URN:NBN: urn:nbn:hr:159:605641
• 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: Open access
• Created on: 2017-04-24 12:30:46