Development of a Protocol for Reducing Carry-Over Effects from Wine in the Mouth.

Using time-intensity methodology, the persistent carry-over effect of astringency noted by earlier investigators was studied. A three-part study examined the effects of rinses of different compositions, concentrations and viscosity levels on astringent perception in the mouth. Trained subjects continuously rated the intensity of an astringent red wine (Indigo Hills, 1998, Merlot) and then proceeded to rinse with different stimuli using a sip and spit method. In Experiment 1, the subjects rinsed with 5 different rinses (pectin (1g/L), PVP (4g/L), ovalbumin (4g/L), gelatin (6g/L) and water). The pectin rinse resulted in the greatest reduction in stimulus intensity after rinsing as compared with the four other rinses. Using the same method, seven rinses of differing concentrations and viscosity levels were tested in Experiment 2 (pectin low (1 g/L), pectin high (5g/L), CMC low (0.01 g/L), CMC high (1 g/L), polycose low (5g/L), polycose high (40g/L) and water). The high pectin rinse was again the most effective at reducing astringent residuals, but was not significantly different from the high CMC rinse or the low pectin rinse. Pectin was tested against crackers, a popular industry interstimulus rinse, and water in Experiment 3. As in Experiments 1 and 2, the pectin rinse resulted in significantly lower stimulus intensity than both the water and cracker rinses. It was concluded that rinses of different composition could reduce astringent perception in the mouth as estimated by most TI parameters. Pectin was found to be the most effective rinse used in this study to decrease the carry over effect and persistent tactile sensation in the mouth, which results from astringent stimuli.