Utjecaj gama - zračenja komine grožđa na parametre kakvoće rakije komovice

master's thesis

• Title (english): Effects of gamma irradiation of grape pomace in quality parameters of grape pomace spirit
• Author: Matej Barić
• Mentor: Marin Mihaljević Žulj (mentor)
• Committee member: Marin Mihaljević Žulj (predsjednik povjerenstva)
• Committee member: Luna Maslov Bandić (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: 2021-07-05, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Istraživanje obuhvaća utjecaj gama zračenja komine grožđa na sastav hlapljivih spojeva nastalih u rakiji komovici. Komina grožđa (Vitis vinifera), sorte 'Chardonnay', tretirana je gama zračenjem u dozama 5, 7 i 10 kGy čime se inhibiralo prirodne mikroorganizme i enzime u komini koji utječu na prekursore odgovorne za nastajanje hlapljivih spojeva u destilatu. Ozračena komina je podvrgnuta alkoholnoj fermentaciji, a zatim destilaciji na jednostavnom destilacijskom uređaju. Koncentracije hlapljivih spojeva utvrđene su plinskim kromatografom sa plameno-ionizacijskim detektorom. Destilati proizvedeni od ozračene komine grožđa imali su smanjene koncentracije hlapljivih spojeva u odnosu na kontrolni uzorak, osim acetaldehida. Uzorak ozračen sa 5 kGy rezultirao je smanjenjem koncentracije metanola za 57%, etil-acetata 14%, viših alkohola za 60% i povećanjem koncentracije acetaldehida za 66%. Kod uzorka tretiranog sa 7 kGy koncentracija metanola smanjena je za 70%, etil-acetata 30% i viših alkohola za 16% te 70% više acetaldehida, dok u uzorku tretiranom sa dozom 10 kGy destilat sadrži 87% manje metanola, 36% manje etil-acetata i 48% manje viših alkohola te 27% više acetaldehida.

Abstract (english)

In this research the effect of gamma irradiation of grape pomace on the volatile compounds in distillate was investigated. Grape pomace from cultivar ‘Chardonnay’ (Vitis vinifera) were treated with gamma irradiation with doses of 5, 7 and 10 kGy which were supposed to inactivate work of natural microflora and enzymes found in grape in order to decrease unwanted and harmful compounds in the distillate. The irradiated grape pomace was subjected to alcoholic fermentation and distillation on ‘Alambic’ distillation apparatus and analysis of volatile compounds were done using gas chromatography. Samples distillated from irradiated fruit showed lower concentrations of volatile compounds. Sample that was irradiated with 5 kGy contained 57% less methanol, 14% less ethyl acetate, 60 % less higher alcohols and 66% more acetaldehyde. Sample irradiated with 7 kGy contained 70% less methanol, 30% less ethyl acetate, 16% less higher alcohols and 70% more acetaldehyde. Sample irradiated with 10 kGy contained 87% less methanol, 36% less ethyl acetate, 48% less higher alcohols and 27% more acetaldehyde.

• Keywords: komovica; gama zračenje; destilat; komina; grožđe
• Keywords (english): gamma irradiation; distillate; grape pomace; grape
• Language: croatian
• URN:NBN: urn:nbn:hr:204:287245
• 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: Open access
• Created on: 2021-09-28 11:28:32