The Ability To Taste Phenylthiocarbamide (Ptc) In Relation To A Common Bitter Substance: Coffee (Cuban Coffee And American Coffee) Research Paper Example

Discussion

In this study used an in vivo multivariable competition assay on two groups of subjects to determine the rates of the dominant allele for the gene associated with PTC sensitivity. There are many pseudogenes that bitter agents can bind (Floriano, 2005). This study wanted to observe a phenotypic trait that reports the sensitivity of bitterness in the tongue. On a molecular level this phenotypic trait can be shown to be from the expression specific G-protein coupled receptors in the tastebuds. PTC tasters were found by using two different kinds of coffee: American coffee and Cuban coffee which contained two different concentrations of caffeine (Bunker, 1979) to first mask the bitterness receptor and then identified the people that perceived PTC at different concentrations. This experiment showed that a cup of Cuban coffee containing a high concentration of caffeine was not be able to mask the receptors for PTC taster. The cup of American coffee had less of an affect on masking the PTC tasting. PTC sensitive people will be able to taste PTC even after a high dose of caffeine.
In this experimental setup groups were not separated based on age, sex, ethnicity or behaviors like smoking. Although these could be all factors in tasting PTC in this study the goal was to observe PTC as a more general phenomenon within this population. Additionally, as there was only had a small number of participants so separating would not have been feasible for this study. However, the results supports similar findings in the PTC research field. In this study it was found that the average of individuals who were sensitive to PTC was 75% when using a 0.003 mg PTC strip and 70.8% with the 0.007 mg PTC strip. Kim et. al (2005; Bufe 2005) reported a PTC sensitivity of 60% in a similarly random population of people. The slight variation in the results was possibly a product of having a relative smaller population sample. This could also be attributed to an experimental error of improper mouth washing between trials. Regardless, it was observed that there were genetic differences within the population used in this study that display a phenotypic response to PTC.
Additionally, the results showed even amongst a smaller sample population that there was a varying degree of PTC sensitivity. Within this population the results showed that not all people can taste PTC and varied from non-tasters to super-tasters (Sato, 1997). This result did not change with the different concentrations of caffeine consumed. A small percentage of the population may not show PTC tasting due a number of factors like smoking, health risks or genetic factors (Shivaprasad, 2012).
Coffee consumption among the sample group who were university students is varied (data not shown). Many students within the sample showed a higher sensitivity to bitterness. There are several possibilities how this group might be different. The first could be was the students may not be exposed to bitter substances like Cuban coffee. The second could be that the students may not consume coffee on a daily basis and if they do they may mask the bitterness of coffee with sugar and milk. The third possibility could be that many of the students used in the study are healthy which has been shown to be an associated factor with tasting bitterness (Kim, 2005). PTC tasting can be used as marker to predict the predisposition of disease traits (Shivaprasad, 2012). Finally the sample group might be specialized (although it was not measured) and certain population groups may be more susceptible to PTC (Davis, 1978; Sato, 1997).
The results showed that after drinking a cup of concentrated Cuban coffee it could better differentiate between PTC tasters and non-tasters. Additionally, it was found that most of the subjects were sensitive to PTC which varied between non-tasters to super-tasters. Although this study used a smaller sample the results showed significant experimental variation that it may be applied to a more general population. These results have implications for future research as it showed that the concentration of caffeine in Cuban coffee could not mask the receptors in PTC tasters and super-tasters. This experiment could be a good test for predicting predisposition of disease traits.

References Cited

Bufe, Bernd, et al. "The molecular basis of individual differences in phenylthiocarbamide and propylthiouracil bitterness perception." Current Biology 15.4 (2005): 322-327.
Davis, R. G. (1978). Increased bitter taste detection thresholds in Yucatan inhabitants related to coffee as a dietary source of niacin. Chemical Senses, 3(4), 423-429.
Kim, U. K., & Drayna, D. (2005). Genetics of individual differences in bitter taste perception: lessons from the PTC gene. Clinical genetics, 67(4), 275-280.
Shivaprasad, H. S., Chaithra, P. T., Kavitha, P., & Malini, S. S. (2012). Role of phenylthiocarbamide as a genetic marker in predicting the predisposition of disease traits in humans. Journal of natural science, biology, and medicine, 3(1), 43.