PT - JOURNAL ARTICLE AU - C. Dartiguenave AU - P. Jeandet AU - A. Maujean TI - Changes in the Buffering Capacity of Model Solutions of 40 m<em>M</em> Tartaric or Malic Acids in Relation to Amino Acids AID - 10.5344/ajev.2000.51.4.347 DP - 2000 Jan 01 TA - American Journal of Enology and Viticulture PG - 347--351 VI - 51 IP - 4 4099 - http://www.ajevonline.org/content/51/4/347.short 4100 - http://www.ajevonline.org/content/51/4/347.full SO - Am J Enol Vitic.2000 Jan 01; 51 AB - The contribution of some amino acids (i.e., arginine, proline, serine, alanine, threonine) to the buffering capacity of wine using model solutions is established. Although amino acids have no buffering capacities at the pH of wine (2.9 to 4.0), they increase the buffering capacity of a 40 mM tartaric acid solution, even at concentrations found in champagne wines. In contrast, when they are added to a 40 mM malic acid solution, they induce no changes in the buffering capacity. It appears that the changes in the buffering capacity depend on the nature of the amino acid used, its concentration, and the medium used. For a 40-mM tartaric acid solution, additions of 400 mg/L of each amino acid increase the buffering capacity from 21% in water to 36.8% in an hydroalcoholic medium (11%, v/v).