The influence of pre-fermentative treatments on the volatile, chromatic features, organic acids and phenolic content of Fetească albă Romanian wine

Ana-Maria Moroşanu,Marius Niculaua,Alexandru Cătălin Tarţian,Cintia Colibaba,Valeriu V Cotea,Camelia Elena Luchian,Jean-Marie Aurand

doi:10.1051/bioconf/20160702017

Abstract

The present study evaluates the influence of some pre-fermentative treatments on the volatile content, the chromatic parameters, the total polyphenol index and Folin-Ciocâlteu index of experimental wines obtained from Feteasca alba grape variety. Five experimental samples were produced: FA V0 (control sample), FA V1 (sodium bentonite treatment), FA V2 (glutathione treatment), FA V3 (tannin treatment), FA V4 (oenological coal treatment). The use of pre-fermentative treatments show lower values of Folin-Ciocâlteu index and total polyphenol index, excepting sample treated with tannin. Major color differences are found in the sample treated with tannin and oenological coal. Gas-chromatographic analysis reveals the presence of common wine esters, such as: hexanoic acid ethyl ester, ethyl caprylate, ethyl lactate, ethyl caprate, ethyl myristate, ethyl palmitate, that contributes at the accomplishment of the wines from the sensorial point of view. Diethyl malonate, a compound that occurs naturally in grapes has an apple-like odor and it was identified in the control sample and in the samples treated with tannin and oenological coal, being found n greater quantity in the control sample (0.02 mmol/L)and the sample treated with coal (0.03 mmol/L). Another ester, methyl oleate that offers a mild-fatty odor wasn't identified in the control sample, but it was detected in the samples treated with clay, tannin and oenological coal. Using the HPLC method it was also analysed the presence of some organic acids in wine samples.

Highlights

The quality of a typical wine depends on the features of the raw material, but strongly depends on winemaking process and especially the treatments applied.Wine is a product of both vineyard and the techniques the winemaker uses and occasionally, aspects of the future wine need to be refined or adjusted
Comparing the wine samples obtained from Feteascaalbavariety in the year 2014 and those obtained in the year 2015 were found important differences concerning the values of alcoholic concentration
If in the case of 2014 Feteascaalbawine samples the values of alcoholic strength parameter were superior than the 11% volume alcohol, in the case of Feteascaalba 2015 the values of this parameter were minor than 11% volume alcohol

Summary

Introduction

Wine is a product of both vineyard and the techniques the winemaker uses and occasionally, aspects of the future wine need to be refined or adjusted. In this case prefermentative treatments are used on wines in order to soften a harsh or astringent character, to improve clarity and to create heat stability. The usage of the fining agents at the right time and in the right doses will increase the probability of obtaining a higher quality product [2] and will decrease the necessity of harsh interventions on the future wine

Objectives

Methods

Results

Conclusion