Every living organism needs information for the maintenance of its life and species. To gather this information animals, including humans, possess senses. By means of these senses they can communicate with their environment. With the senses of smell and taste the animal world communicates via chemicals. Chemical communication plays an important role in locating food, in inter-individual relations (social and sexual) and in detecting danger. With the chemical senses one may assume that a chemical substance (or mixture) interacts with a biological system resulting in a response. Human olfaction concerns the odor perception by human beings.
Our senses of smell and taste are chemical senses, which means chemicals trigger them. During human olfaction, one can study detection, quality, intensity and preference of natural isolates and chemical molecules. For the detection of odorants, threshold values are determined in various media. Thousands of threshold values were studied from published data. Wide ranges of threshold values have been found for the same products. Threshold values are important for the calculation of the aroma value of chemical constituents in flavors. A scheme for the quantification of odor aspects of aroma chemicals has been proposed. Why? Because there exists confusion about odor descriptions and qualifications, due to the fact that human beings have not learned how to smell or taste in a more sophisticate way, and because personal psychological aspects of subjects (mentioned before) cannot be controlled. Odor intensity and appreciation studies can be used for the determination of the olfactive-value-for-money of aroma chemicals.
[ See for the full article: Perfumer & Flavorist, Volume 27, Number 4, July/August 2002. ]
Reprinted by Leffingwell & Associates, 2006, with Permission