Effect of Maceration Conditions on Chemical Composition and Colour Characteristics of Merlot Wines

Abstract

Due to their complex composition, Merlot cultivar red grapes were subjected to maceration-fermentation as an important stage for the natural pigments and aroma compounds extraction. The purpose of this paper was the assessment of three pre-fermentation maceration techniques in order to improve wine's characteristics. For the experiment were used Merlot cultivar red grapes. The grapes were removed from their clusters, crushed and than transferred to three maceration techniques: microwave maceration at 650 W for 15 minutes, thermal maceration by heating the grape grains at 70 ⁰C for 20 minutes and classical maceration for 7 days at 20 ⁰C. During the process of maceration and fermentation all the samples were monitored considering the yeast cell count and alcohol content. The wine samples were evaluated in terms of colour, by spectrophotometric method. The evaluation of technological index, the evolution of the yeast cells and the fermentation parameters from the three samples indicate that the most advantageous fermentation procedure was classical maceration-fermentation.