Utjecaj oplodnje na sadržaj polifenola u grožđu cv. Grk (V. vinifera L.)

master's thesis

• Author: Valentina Ivetac
• Mentor: Edi Maletić (mentor)
• Committee member: Edi Maletić (predsjednik povjerenstva)
• Committee member: Darko Preiner (član povjerenstva)
• Committee member: Jasminka Karoglan-Kontić (član povjerenstva)
• Committee member: Domagoj Stupić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Department of Viticulture and Enology); Zagreb
• Defense date and country: 2016-07-13, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy; Viticulture and Enology

Abstract

Grk je autohtona sorta vinove loze čije je najvažnije područje uzgoja u Lumbardi na otoku Korčuli. Specifična je zbog funkcionalno ženskog cvijeta koji sadrži povijene prašnike a pelud je sterilna. Zbog nefunkcionalne peludi ne dolazi do pravilne oplodnje te se na grozdu razvijaju male, besjemene bobice, poznate kao “pasoline”. Omjer „pasolina“ i normalno oplođenih, velikih, bobica u grozdu može biti različit. Ime sorte „Grk“ povezuje se sa lokalnim sinonimom „gark“ odnosno „gorak“ jer vino posjeduje određenu dozu gorčine. Pretpostavka za gorčinu u vinu upravo je pojava malih besjemenih bobica. Ovim je istraživanjem utvrđen sadržaj polifenola, kao nosiocima okusa gorčine, u kožicama i moštu oba tipa bobica. Istraživanjem je utvrđeno da meso malih, besjemenih bobica sadrži više kaftarinske i kafeinske kiseline te katehina. Također, utvrđeno je da je sadržaj flavan-3-ola kod sorte Grk viši u odnosu na ranija istraživanja kod ostalih bijelih sorata iz sličnoga područja uzgoja. Stoga, flavan-3-oli predstavljaju potencijalne nosioce gorčine u vinu kod ove sorte.

Abstract (english)

Grk is indigenous grape variety which is most cultivated in the area of Lumbarda, on the island of Korčula. It is specific for functional female flower, which contains bent stamens and pollen is sterile. Due to the non-functional pollen does not come to the correct fertilization and cluster develops two types of berries: small, seedless berries, known as "pasoline" and normally fertilized, large, berries. The ratio of those two types of berries in a cluster can be different. Variety name "Grk" is associated with a local synonym "gark" or "bitter" because wine has a certain amount of bitterness. The assumption of bitterness in wine has just the appearance of small, seedless berries. This research determined the content of polyphenols, as carriers of bitterness. Anlayzed material includes skin and must of both types of berries. The study found that the meat of small, seedless berries contains great concentration of caftaric and caffeic acid and catechin. It was also found that the content of flavan-3-ol group of polyphenols in this cultivar is higher than in other white skin cultivars from similar area of cultivation. Therefore, flavan-3-ols are potential carriers of bitterness in wine of this variety.

• Keywords: vinova loza; Grk bijeli; polifenoli
• Keywords (english): vine; Grk; polyphenols
• Language: croatian
• URN:NBN: urn:nbn:hr:204:100484
• Study programme: Title: Horticulture; Study programme type: university; Study level: graduate; Academic / professional title: magistar/ magistra inženjer/inženjerka hortikulture (magistar/ magistra inženjer/inženjerka hortikulture)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Repository: Repository Faculty of Agriculture University of Zagreb
• Created on: 2016-09-07 06:48:22