The Time-Course of Astringency in Wine upon Repeated Ingestion

Abstract

Using a computerized technique for time-intensity (TI) measurements, the effects of three successive ingestions on the time-course of astringency of 0, 250, and 500 mg/L of tannic acid in white wine were measured by 10 judges. Time intervals of 5 or 30 seconds were programmed between the end of one sample evaluation and the beginning of the next. Upon repeated ingestion, total duration of astringency increased significantly (p < 0.001), whereas maximum intensity and time to maximum intensity did not change. Maximum intensity of astringency increased significantly (p < 0.001) with concentration of added tannic acid. No significant difference was found between the 5- and 30-second delays between samples for total duration, maximum intensity, and time to maximum intensity of astringency. In a second experiment, the effects on temporal astringency of three successive ingestions of wine containing 0 and 500 mg/L of tannic acid, served as 8- or 15-mL samples, were measured by eight trained judges. Time intervals of 20 or 40 seconds were programmed between ingestions with continuous TI data collection. Maximum intensity of astringency and intensity at ingestion increased significantly (p < 0.001) upon repeated ingestion and with concentration of added tannic acid. Sample size did not affect temporal astringency of wine upon repeated ingestion. Intensity of astringency at ingestion decreased significantly (p < 0.001) when time between ingestions was increased from 20 to 40 seconds.