Impact of the timing and the nature of nitrogen additions on the production kinetics of fermentative aromas by Saccharomyces cerevisiae during winemaking fermentation in synthetic media

Abstract

During alcoholic fermentation, many parameters, including the nitrogen composition of the must, can affect aroma production. The aim of this study was to examine the impact of several types of nitrogen sources added at different times during fermentation. Nitrogen was added as ammonium or a mixture of amino acids at the beginning of fermentation or at the start of the stationary phase. These conditions were tested with two Saccharomyces cerevisiae strains that have different nitrogen requirements. The additions systematically reduced the fermentation duration. The aroma production was impacted by both the timing of the addition and the composition of the nitrogen source. Propanol appeared to be a metabolic marker of the presence of assimilable nitrogen in the must. The production of ethyl esters was slightly higher after the addition of any type of nitrogen; the production of higher alcohols other than propanol was unchanged, and acetate esters were overproduced due to the overexpression of the genes ATF1 and ATF2. Finally the parameter affecting the most the synthesis of beneficial aromas was the addition timing: The supply of organic nitrogen at the beginning of the stationary phase was more favorable for the synthesis of beneficial aromas.

Nitrogen Sources Added to Must: Effect on the Fermentations and on the Tempranillo Red Wine Quality

“…Nevertheless, significant differences were not found after AF due to the addition of organic nitrogen to the must (Table 2) compared to control. These data differ from those obtained in the same conditions by Seguinot et al [23] who found that organic nitrogen addition significantly increased the production of propanol and isoamyl acetate, even more than ammonium addition. Differences with our results could be due to the type of nitrogen used in both studies.…”

“…These results do not coincide with other studies carried out about this topic, which have reported that nitrogen addition affect fermentation rate either enhancing the fermentation activity or the number of cells [1,10,20]. Varela et al [33] concluded that the increase in viable cell concentrations positively correlated with the increase in fermentation rates and Seguinot et al [23] showed that the nitrogen additions systematically reduced the fermentation duration. However, in another work carried out by López et al [34], in which the addition of different doses (15, 30, and 60 g/hL) of DAP was studied for three consecutive vintages in musts of the Viura variety, the additions did not produce significant modifications neither in the spontaneous fermentative kinetics nor in the number of yeasts.…”

“…In our work, significant differences were not found neither in pH nor in glycerol content. In this aspect, Perez et al [20] indicated that the addition of 200 mg/L of ammonium salt showed the lower levels of pH while Chen et al and Ugliano and Henschke [13,46] reported that ammonium additions led to the higher production of glycerol, but Vilanova et al and Seguinot et al showed an insignificant effect [22,23].…”

“…Most of references found about this topic have refer to adding inorganic nitrogen (ammonium salts) at the beginning of fermentation. Nevertheless, [23] indicated that the aroma production was impacted both the timing of the addition and the composition of the nitrogen source.…”

Determination of Nutrient Supplementation by Means of ATR-FTIR Spectroscopy during Wine Fermentation

“…On the other hand, a late addition may prevent the sugar transportation and its assimilation by the yeast cells [22]. The timing and also the nature of nitrogen are important factors on the fermentation kinetics, being the organic source the most adequate in some cases [23]. However, the addition inorganic nitrogen sources, mainly the ammonium chloride and the diammonium phosphate salts, can reduce the slow down fermentation risks and the formation of undesirable sulphur compounds [8,13] and improve the aromatic profile of wines [20].…”