magistrsko delo
Iva Levačić (Author), Lea Pogačnik (Reviewer), Tatjana Košmerl (Mentor)

Abstract

Rdeča vina običajno zorijo v lesenih sodih z namenom izboljšanja senzoričnih lastnosti, alternativni postopek pa je lahko tudi vpihovanje kisika oziroma mikrooksigenacija in/ali dodatek trsk iz hrastovega lesa. Namen magistrske naloge je bil ugotoviti optimalne pogoje vpihovanja kisika in dodatka trsk iz hrastovega lesa na fenolne spojine, aromatski profil in stabilizacijo barve rdečega vina refošk. Praktični del poskusa je obsegal zorenje vina v štirih cisternah iz nerjavnega jekla z različnimi režimi vpihovanja kisika in dodatka trsk iz hrastovega lesa. Fenolne značilnosti vina smo določili z analizami skupnih fenolov, netaninskih fenolov, skupnih antocianinov, neflavonoidnih fenolov, proantocianidinov, z določitvijo vanilin indeksa, povprečne stopnje polimerizacije in deleža prodelfinidinov ter galoilacije. Barvne značilnosti vina smo določili z analizami intenzitete in tona barve, deleža rdeče barve v obliki flavilijevega kationa, deleža rdeče barve brez vpliva vezave SO2 na barvila, deleža rdečega barvila in barve vina pri valovnih dolžinah 420 nm, 520 nm in 620 nm ter motnosti vina. Na koncu praktičnega dela smo izvedli senzorično analizo vzorcev vina s strokovno komisijo šolanih preskuševalcev po metodi RATA in metodi razvrščanja. Med zorenjem se je vsem vzorcem vina zmanjšala koncentracija skupnih fenolnih spojin in skupnih antocianinov. Na izboljšanje fenolnih in barvnih značilnosti vina je pozitivno vplival predvsem dodatek trsk iz hrastovega lesa in kombinacija največjega odmerka vpihovanega kisika z dodatkom trsk iz hrastovega lesa. Pri senzorični analizi je bilo najbolje ocenjeno vino, ki smo mu vpihovali največjo količino kisika z dodatkom trsk iz hrastovega lesa.

Keywords

vino;refošk;mikrooksigenacija;kisik;trske iz hrastovega lesa;fenoli;tanini;antocianini;senzorične lastnosti;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [I. Levačić]
UDC: 663.256/.257:543.2/.9
COBISS: 115421955 Link will open in a new window
Views: 80
Downloads: 41
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Other data

Secondary language: English
Secondary title: Influence of microoxygenation and addition of oak chips on the maturation of Refosco wine
Secondary abstract: Red wines are usually matured in wooden barrels to improve sensory characteristics. An alternative process can be microoxygenation and/or the addition of oak chips. The objective of the Master's thesis was to determine the optimal conditions for microoxygenation and the addition of oak chips to the development of phenolic compounds, aromatic profile and color stabilization of Refosco wine. The practical part of the experiment consisted of maturing the wine in four stainless steel tanks with different oxygen concentration and the addition of oak chips. The phenolic characteristics of the wine were determined by analyzes of total phenolics, non-tannins, total anthocyanins, non-flavonoids, proanthocyanidins, vanillin index, mean degree of polymerization and percentage of prodelphinidins and galloylation. The color characteristics of the wine were determined by analysing the color density, color hue, percentage of red color in the form of flavylium cation, estimation of SO2 content, percentage of red pigment, degree of red pigment coloration at different wavelengths (420 nm, 520 nm and 620 nm) and turbidity. At the end of the practical part, we performed a sensory analysis of the wine samples using the method RATA and the ranking method with a commission of trained experts. During maturation of the wine, the concentration of total phenols and total anthocyanins decreased in all wine samples. The improvement of the phenolic and color characteristics of the wine was mainly influenced by the addition of oak chips and the combination of the highest concentration of added oxygen with the addition of oak chips. Sensory analysis showed that the wine sample microoxygenated with the highest concentration of oxygen and the added oak chips received the best overall score.
Secondary keywords: wines;Refosco wine;microoxygenation;oxygen;oak chips;phenols;tannins;anthocyanins;sensory properties;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: 1 spletni vir (1 datoteka PDF (XII, 64 str., [15] f. pril.))
ID: 15907839