EFFECTIVENESS OF RINSES IN ALLEVIATING BITTERNESS AND ASTRINGENCY RESIDUALS IN MODEL SOLUTIONS

A two-part study determined the effectiveness of gum-based rinses with or without oil for alleviating residuals of a bitter (0. 8 g/L caffeine solution) and an astringent (1g/L alum solution) stimuli in serial responses using a sip and spit method. In Experiment 1, rinsing with deionized water was compared to rinsing with 0.3% xanthan gum in water alone or with 5% corn oil and 0.55% carboxymethyl cellulose (CMC) in water alone or with 5% or 10% corn oil. The 0.3% xanthan gum and 5% corn oil mixture resulted in the highest stimulus intensity difference before and after rinsing, whereas 0.55% CMC had a value of nearly zero for residual effect. Results of a two-alternative forced choice test used in Experiment 2 indicated that both were equally effective for reducing bitterness residuals, but 0.55% CMC solution resulted in the lowest (p=0.007) residual effect for astringency. Therefore, the 0.55% CMC rinse was considered an effective interstimulus rinse to use for assessing both bitterness and astringency in model solutions. L'efficacite d'un rincage avec une solution composee de gomme xanthane, avec ou sans huile de mais et de carboxymethylcellulose (CMC) sur la diminution de l'amertume (cafeine) et de l'astringence (alun) residuelle est teste. Le rincage a 0,55% de CMC est le plus actif, puisque l'effet residuel est proche de 0.