Location: Horticultural Crops Research UnitTitle: Effects of soil NPK supply on Pinot Noir wine phenolics and aroma composition
|YUAN, FANG - Oregon State University|
|Schreiner, R Paul|
|OSBORNE, JAMES - Oregon State University|
|QIAN, MICHAEL - Oregon State University|
Submitted to: American Journal of Enology and Viticulture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/11/2018
Publication Date: 5/29/2018
Citation: Yuan, F., Schreiner, R.P., Osborne, J., Qian, M. 2018. Effects of soil NPK supply on Pinot Noir wine phenolics and aroma composition. American Journal of Enology and Viticulture. 69(4):371-385. https://doi.org/10.5344/ajev.2018.17077.
Interpretive Summary: The impact of varying levels of nitrogen, phosphorus, and potassium on aroma compounds present in Pinot Noir wines was examined as part of a study to better define grapevine requirements for these nutrients. Nitrogen supply affected wine aroma composition to a far greater extent than either phosphorus or potassium supply. Nitrogen mainly altered aroma compounds that are produced by yeast metabolism. Wines produced from vines that had lower nitrogen status had lower levels of straight-chain esters and alcohols, but higher levels of branched-chain esters and alcohols. Low N wines also had reduced levels of volatile sulfur compounds that are known to impart unpleasant odors in wine, opposite of conventional wisdom. These findings indicate that the nitrogen status of Pinot Noir alters the final aroma composition in wines and that this effect should be considered along with impacts on vine productivity for developing tissue test guidelines for managing nitrogen. Phosphorus and potassium status of vines has limited impact on wine aroma composition.
Technical Abstract: This work evaluated the impact of vine nitrogen (N), phosphorous (P) and potassium (K) supply on Pinot noir wine composition. Pinot noir grapevines were grown in a pot-in-pot system for three years and fertigated with varying levels of either N, P, or K supply while holding all other nutrients constant. Nitrogen was varied from 7.50 mM total N supply (Control) to as low as 1.125 mM total N in five discreet levels, while P and K supply were each varied in four levels with the lowest rate of 0 mM during fertigation events. Wines from each of the three years were analyzed. N supply had major impact on wine composition. Reducing N supply increased the total phenolic content in wine across all years. N supply affected wine volatile composition with the greatest effect on fermentation-derived esters and higher alcohols. In general, reducing N supply decreased straight-chain esters and alcohols, but increased the branched-chain esters and alcohols in wine. The total odor activity value for the esters decreased with low N supply. Low N wines also had reduced levels of volatile sulfur compounds in two of the three years. N supply affected some grape-derived compounds. Reducing N supply resulted in lower concentrations of total ß-damascenone across all years, but the effect of N supply on monoterpenes was not consistent from year to year. Altering P supply did not have reproducible effects on wine volatiles. The volatile composition change in response to nutrient supply could ultimately affect aroma perception and overall wine quality, which will require further exploration.