Bely Marina, Rinaldi Alessandra, Dubourdieu Denis
Faculté d'Oenologie, Université Victor Segalen Bordeaux 2, 351 Cours de la Libération, 33405 Talence, France.
J Biosci Bioeng. 2003;96(6):507-12. doi: 10.1016/S1389-1723(04)70141-3.
We analyzed the variability of volatile acidity and glycerol production by Saccharomyces cerevisiae on a large sample of high sugar musts. The production of volatile acidity was inversely correlated with the maximum cell population and the assimilable nitrogen concentration. The higher the nitrogen concentration, the less volatile acidity was produced. An approach to minimize volatile acidity production during high sugar fermentations by adjustment of assimilable nitrogen in musts was investigated in terms of both quantity and addition time. It was found that the optimal nitrogen concentration in the must is 190 mgN.l(-1). The best moment for nitrogen addition was at the beginning of fermentation. Addition at the end of the growth phase had less effect on volatile acidity reduction. We suggest that by stimulating cell growth, nitrogen addition provides NADH in the redox-equilibrating process, which in turn reduces volatile acidity formation.
我们分析了酿酒酵母在大量高糖葡萄汁样本上挥发性酸度和甘油产量的变异性。挥发性酸度的产生与最大细胞群体数量和可同化氮浓度呈负相关。氮浓度越高，产生的挥发性酸度越少。从数量和添加时间两方面研究了通过调整葡萄汁中可同化氮来尽量减少高糖发酵过程中挥发性酸度产生的方法。结果发现，葡萄汁中的最佳氮浓度为190 mgN.l(-1)。添加氮的最佳时机是在发酵开始时。在生长阶段结束时添加对降低挥发性酸度的效果较小。我们认为，通过刺激细胞生长，添加氮在氧化还原平衡过程中提供了NADH，进而减少了挥发性酸度的形成。
