Sample preparation and evaluation conditions
In the laboratory, the wines were placed in a cellar (17 ± 2 °C) until being analyzed. Bottles were opened just before serving the wines. Standardized 200-mL wine-tasting glasses (ISO, 1977) were used. Volumes of 35 ± 4 mL and 25 ± 1 mL were served by using volumetric pourers for tasting and for appearance evaluation, respectively. Glasses were covered with Petri dishes to avoid volatile losses and were presented codified with three digits. Water and unsalted crackers were provided to the assessors to eliminate residual sensations between samples.
According to the purpose of each step, wines were evaluated in the group room or in a room with seven booths equipped with computer terminals. In the booth room, both temperature (21 ± 2 °C) and relative humidity (60 ± 20%) were controlled. Olfactory and gustatory evaluation was carried out firstly under the weak light provided by the computer screen to avoid any colour bias. Appearance evaluation was carried out by using additional glasses and under lighting similar to daylight (colour temperature very close to 6500 K and chromatic rendering index higher than 90).
Through the method development wines were scored in paper cards. Once the definitive score card was defined, data from wines evaluated in booths were collected with FIZZ software (Biosystèmes, Couternon, Version 2.10 A).