Saccharomyces cerevisiae vineyard strains have different nitrogen requirements that affect their fermentation performances
Lemos Junior, W.J.F. | Viel, A. | Bovo, B. | Carlot, M. | Giacomini, A. | Corich, V.
In this work the fermentation performances of seven vineyard strains, together with the industrial strain EC1118, have been investigated at three differing yeast assimilable nitrogen (YAN) concentrations (300Â mgÂ NÂ lâ»Â¹, 150Â mgÂ NÂ lâ»Â¹ and 70Â mgÂ NÂ lâ»Â¹) in synthetic musts. The results indicated that the response to different nitrogen levels is strain dependent. Most of the strains showed a dramatic decrease of the fermentation at 70Â mgÂ NÂ lâ»Â¹ but no significant differences in COâ production were found when fermentations at 300Â mgÂ NÂ lâ»Â¹ and 150Â mgÂ NÂ lâ»Â¹ were compared. Only one among the vineyard strains showed a decrease of the fermentation when 150Â mgÂ NÂ lâ»Â¹ were present in the must. These results contribute to shed light on strain nitrogen requirements and offer new perspectives to manage the fermentation process during winemaking. SIGNIFICANCE AND IMPACT OF THE STUDY: Selected vineyard Saccharomyces cerevisiae strains can improve the quality and the complexity of local wines. Wine quality is also influenced by nitrogen availability that modulates yeast fermentation activity. In this work, yeast nitrogen assimilation was evaluated to clarify the nitrogen requirements of vineyard strains. Most of the strains needed high nitrogen levels to express the best fermentation performances. The results obtained indicate the critical nitrogen levels. When the nitrogen concentration was above the critical level, the fermentation process increased, but if the level of nitrogen was further increased no effect on the fermentation was found.Show more [+] Less [-]