Abstract
Today, the demand is oriented towards wines with fruity and floral sensory profiles. In order to meet consumer expectations, it is necessary to develop strategies to control the winemaking process to obtain the desired organoleptic properties. The general objective of this work is therefore to study the individual and combined effects of two key fermentation parameters on yeast metabolism and fermentation aroma synthesis: nitrogen and temperature. The first part of this thesis was devoted to studying the impact of the nitrogen addition timing during fermentation on the synthesis of aroma compounds by the yeast. In this sense, a study combining statistical modeling and analysis of the expression of genes involved in the aroma synthesis by yeast allowed us to determine the optimal timing of the nitrogen addition nitrogen during fermentation in order to maximize the content of positive aromas (mainly acetate esters). Then, an evaluation of the combined effects of nitrogen and temperature on yeast metabolism was carried out thanks to an online monitoring tool for fermentative aromas. An ideal synthesis temperature was identified for each compound monitored. Finally, the examination of the impact of nitrogen addition and temperature on fermentation and aroma kinetics for fermentation control was extended to the study of anisothermal temperature profiles. Profiles including a decrease in temperature were identified as the most favorable for the synthesis and accumulation of ethyl esters in the liquid.