Analysis of volatile compounds production kinetics: A study of the impact of nitrogen addition and temperature during alcoholic fermentation.

Among the different compounds present in the must, nitrogen is an essential nutrient for the management of fermentation kinetics, also playing a major role in the synthesis of fermentative aromas. Fermentation temperature is yet another variable that affects fermentation duration and the production of fermentative aromas in wine. The main objective of this study was thus to evaluate the combined effects of nitrogen addition-at the start of the fermentation process or during the stationary phase-at different fermentation temperatures on both fermentation kinetics and aroma synthesis kinetics.

L. Diversity for Cations and Acidity Is Suitable for Breeding Fruits Coping With Climate Warming.

The selection of grapevine varieties is considered to be the smartest strategy for adapting the viticulture to climate warming. Present knowledge of the diversity of grape solutes known to be influenced by temperature is too limited to perform genetic improvement strategies. This study aimed to characterize the diversity for major cations (K, Mg, Ca, NH ) of the fruit and their effect on acidity.

Comprehensive Study of the Evolution of the Gas-Liquid Partitioning of Acetaldehyde during Wine Alcoholic Fermentation.

Determining the gas-liquid partitioning ( K) of acetaldehyde during alcoholic fermentation is an important step in the optimization of fermentation control with the aim of minimizing the accumulation of this compound, which is responsible for the undesired attributes of green apples and fresh-cut grass in wines. In this work, the effects of the main fermentation parameters on the K of acetaldehyde were assessed. K values were found to be dependent on the temperature and composition of the medium.

L. Fruit Diversity to Breed Varieties Anticipating Climate Changes.

The wine industry is facing critical issues due to climate changes since production is established on very tight Genotype × Environment interaction bases. While, some cultivation practices may reduce adverse effects of abiotic stresses on the vines, e.g.

Prevention of volatile fatty acids production and limitation of odours from winery wastewaters by denitrification.

The effect of the addition of nitrate to winery wastewaters to control the formation of VFA in order to prevent odours during storage and treatment was studied in batch bioreactors at different NO(3)/chemical oxygen demand (COD) ratios and at full scale in natural evaporation ponds (2 x 7000 m(2)) by measuring olfactory intensity. In the absence of nitrate, butyric acid (2304 mgL(-1)), acetic acid (1633 mgL(-1)), propionic acid (1558 mgL(-1)), caproic acid (499 mgL(-1)) and valeric acid (298 mgL(-1)) were produced from reconstituted winery wastewater. For a ratio of NO(3)/COD=0.