Abstract:

Seventeen amino acids in 14 cultivars of white wine grapes were detected using an amino acid analyzer. The
results showed that total content of amino acids in white wine grapes ranged from 1128.550 (Grey Riesling) to 4967.779
mg/100 g fresh weight (Pinot Blanc). Pro, Arg, Ser, Thr and Glu were the major amino acids in white wine grapes with the
richest Pro content (48% of the total content among 17 amino acids), regardless of the cultivar or growing area. However,
Met, Phe and Tyr indicated lower concentrations than other amino acids. In addition, Pro was richer in all 14 cultivars than
Arg. Pro and Pro/Arg ratio (δ) exhibited obvious variation among different cultivars. The concentrations of aroma-related
amino acids were different among 14 cultivars of white wine grapes, which showed the highest level in Chardonnay, the
second highest level in Pinot Blanc, and the lowest level in Grey Riesling.

Key words: wine grape, amino acid content, compositional characteristics of amino acids