Seasonal variation in amino acid and phenolic compound profiles of three Turkish white wine grapes

Changes in amino acids and phenolic compounds in Emir, Narince, and Sultaniye grapes were monitored by high-performance liquid chromatography for two consecutive seasons. Seasonal and varietal variations in amino acid content were observed among the cultivars. Arginine, histidine, and alanine were the most prominent amino acids in all 3 cultivars in both years, with arginine being the highest found in the Sultaniye cultivar, varying between 910 and 955 mg/L. The phenolic contents also showed seasonal and varietal variations. Of the phenolic compounds identified, catechin was the most abundant in all three cultivars, with the highest found in Narince ranging between 106 and 109 mg/kg. Procyanidin B1 and gallic acid were the second most prominent.Changes in amino acids and phenolic compounds in Emir, Narince, and Sultaniye grapes were monitored by high-performance liquid chromatography for two consecutive seasons. Seasonal and varietal variations in amino acid content were observed among the cultivars. Arginine, histidine, and alanine were the most prominent amino acids in all 3 cultivars in both years, with arginine being the highest found in the Sultaniye cultivar, varying between 910 and 955 mg/L. The phenolic contents also showed seasonal and varietal variations. Of the phenolic compounds identified, catechin was the most abundant in all three cultivars, with the highest found in Narince ranging between 106 and 109 mg/kg. Procyanidin B1 and gallic acid were the second most prominent