title: Comparison of inorganic and organic nitrogen supplementation of grape juice - Effect on volatile composition and aroma profile of a Chardonnay wine fermented with Saccharomyces cerevisiae yeast.
abstract: Inorganic nitrogen salts, and to a growing extent organic nitrogen preparations, are widely used to ameliorate a nitrogen deficiency in wine fermentation, but the impact of nitrogen supplementation on perceived wine sensory profile is essentially unknown. Supplementation of a low nitrogen Chardonnay grape juice with either ammonium nitrogen or combined amino acid and ammonium nitrogen showed that the type of nitrogen and concentration in the range 160-480mgN/l had a substantial impact on the formation of yeast volatile compounds and perceived wine aroma. Addition of amino acid and ammonium nitrogen increased both acetate and medium chain fatty acid esters to a greater extent and decreased higher alcohols to a lesser extent than ammonium nitrogen alone whereas ammonium nitrogen substantially increased ethyl acetate and acetic acid. Low nitrogen wines were rated relatively low in floral/fruity aroma descriptors, while moderate nitrogen wines showed a good balance between desirable and less desirable attributes, whereas high nitrogen produced either an acetic/solvent character or highest ratings for floral/fruity attributes, depending on nitrogen type. These results show that amount and type of nitrogen supplement can substantially modulate Chardonnay wine volatiles composition and perceived aroma.
authors.affiliation: Australian Wine Research Institute, P.O. Box 197, Glen Osmond (Adelaide), SA 5064, Australia; Universidad Pubica de Navarra, Department of Applied Chemistry, Campus Arrosadia S-N, E-31006 Pamplona, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Torrea
authors.affiliation: Australian Wine Research Institute, P.O. Box 197, Glen Osmond (Adelaide), SA 5064, Australia.
authors.forename: Cristian
authors.initials: C
authors.lastname: Varela
authors.affiliation: Australian Wine Research Institute, P.O. Box 197, Glen Osmond (Adelaide), SA 5064, Australia.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Ugliano
authors.affiliation: Universidad Pubica de Navarra, Department of Applied Chemistry, Campus Arrosadia S-N, E-31006 Pamplona, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Ancin-Azpilicueta
authors.affiliation: Australian Wine Research Institute, P.O. Box 197, Glen Osmond (Adelaide), SA 5064, Australia.
authors.forename: I
authors.initials: I
authors.lastname: Leigh Francis
authors.affiliation: Australian Wine Research Institute, P.O. Box 197, Glen Osmond (Adelaide), SA 5064, Australia. Electronic address: paul.henschke@awri.com.au.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Henschke
keywords: Aroma; Chardonnay; Fermentation; Flavour; Nitrogen; Saccharomyces cerevisiae; Wine; Yeast