12-1 |
Effect of 6-n propyl thiouracil (PROP) sensitivity on astringency perception |
E. M. CUBERO-CASTILLO, Food Technology, University of Costa Rica, Escuela de Tecnologia de Alimentos. San Pedro de Montes de Oca, San Jose, Costa Rica Sensitivity to PROP is an inherited trait. Recent studies have identified three potential taster categories: non-tasters, medium-tasters and super-tasters. Super-tasters had higher density of fungiform papillae and higher number of taste pores per taste papillae than PROP tasters, who in turn had higher values than PROP non-tasters. Besides, 25% of the innervation of fungiform papillae comes from the chorda tympani (taste) and 75% from the trigeminal nerve (pain, touch, temperature). Given the dual innervation of fungiform papillae, it is not surprinsing that irritants like capsaicin and ethanol produce the greatest burn sensation to super-tasters and the least to non-tasters. Since astringency sensations are tactile sensations that are perceived by trigeminal nerve mechanoreceptors, it is possible that there may be a relationship between perception of PROP and perception of astringency. The objective was to study the relationship between PROP sensitivity and perceived astringency of aluminum sulfate. PROP thresholds and the ratio of perceived bitterness of 2 PROP solutions to the perceived saltiness of 2 salt solutions were measured in eighty subjects. The astringency of 3 aluminum sulfate solutions were rated in the LMS scale. The results showed that there was not a significant effect between PROP sensitivity and astringency perception in average. The effect was minimized by a context effect exerted by PROP solutions used for classification into PROP status. Medium-tasters and non-tasters did not have the context effect. When the effect was eliminated by presenting the astringent solutions before the PROP solutions, there is not significant differences between super-tasters and medium-tasters while there is a significant difference between them and non-tasters for the 2 higher astringent solutions and no effect for the lower solution. These results suggest that the relationship between PROP and tactile sensations are due to trigeminal nerve and not to taste sensations only.
Session 12, Sensory Evaluation: Sensory techniques - Descriptive analysis
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