Impact of Nitrogen and Elemental Sulfur on Formation of Volatile Sulfur Compounds during Fermentation of Pinot Noir Grapes

oleh: Daniel Kraft, Qin Zhou, Michael Qian, James Osborne

Format: Article
Diterbitkan: MDPI AG 2023-10-01

Deskripsi

The influence of yeast assimilable nitrogen (YAN) and elemental sulfur (S<sup>0</sup>) on the formation of volatile sulfur compounds (VSCs) during fermentation was investigated. Pinot noir fermentations were performed using <i>Saccharomyces cerevisiae</i> strain UCD522 or P1Y2 with an addition of 0, 5, or 15 µg/g elemental sulfur. H<sub>2</sub>S production during fermentation was measured using lead acetate tubes and additional VSCs measured by GC-PFPD. The addition of S<sup>0</sup> resulted in H<sub>2</sub>S formation during alcoholic fermentation regardless of which yeast strain was used. H<sub>2</sub>S production was greater in fermentations performed by UCD522 with increasing amounts of S<sup>0</sup> resulting in increased production of H<sub>2</sub>S. Higher S<sup>0</sup> resulted in wines containing higher concentrations of methyl thioacetate and glutathione disulfide. Additional experiments examined the impact of nitrogen composition and S<sup>0</sup>. The addition of diammonium phosphate (DAP) resulted in an increase in H<sub>2</sub>S formation during fermentation whereas the addition of amino acids did not, whether S<sup>0</sup> was added or not. Fermentations where DAP and S<sup>0</sup> were both added produced a higher concentration of H<sub>2</sub>S compared to fermentations where S<sup>0</sup> or DAP additions were made individually. VSCs in the wine were also impacted by the addition of nitrogen and/or S<sup>0</sup> with the addition of S<sup>0</sup> and nitrogen (DAP or amino acids) resulting in elevated concentrations of methyl thioacetate in the wines.