Odor detection threshold

Source: Wikipedia, the free encyclopedia.

The odor detection threshold is the lowest concentration of a certain

sense of smell. The threshold of a chemical compound is determined in part by its shape, polarity, partial charges, and molecular mass
. The olfactory mechanisms responsible for a compound's different detection threshold is not well understood. As such, odor thresholds cannot be accurately predicted. Rather, they must be measured through extensive tests using human subjects in laboratory settings.

gas chromatographs
.

For raw water treatment and waste water management, the term commonly used is Threshold Odor Number (TON). For instance, the water to be supplied for domestic use in Illinois is 3 TON.[1]

Values

  • The
    threshold value
    is the concentration at which an aroma or taste can be detected (air, water and fat).
  • The
    olfactory neurons
    is the concentration at which you can identify an odor (air, water and fat).
  • The odour activity value is the concentration divided by the threshold.
  • The flavor impact is the value the rate of change in perception with concentration.
  • The flavor contribution of an aroma component in a mixture to the total profile can be calculated from the total odor units and the number contributed by that aroma chemical.

Odor detection value

Odor threshold value (OTV) (also aroma threshold value (ATV), Flavor threshold) is defined as the most minimal

Olympic swimming pool
. Odor threshold value can be expressed as a concentration in water or concentration in air.

Two major types of flavor thresholds can be distinguished: the absolute and the difference threshold. The odor detection threshold and the odor recognition threshold are absolute thresholds; the first is the minimum concentration at which an odor can be detected without any requirements to identify or recognize the stimulus, while the second is the minimum concentration at which a stimulus can be identified or recognized.[2]

The odor threshold value of an odorant is influenced by the medium.

Examples of substances with strong odors:

Variables

Threshold in a food is dependent upon:

The concentration of an odor above a food is dependent on its solubility in that food and its vapor pressure and concentration in that food.

Variation by individual

A 2014 study found no significant differences between men and women, and between non-pregnant and pregnant individuals, despite the existence of anecdotal reports of hyperosmia among the latter.[7]

People with

Multiple Sclerosis have been found to have higher olfactory thresholds. In scientific research, this is often represented by a lower threshold score, i.e. reversing the scale. Olfactory function is more impaired in patients with primary progressive MS than that in relapsing-remitting MS.[8]

Variation among species

Some species can detect odors that others cannot. It is widely believed that animals such as dogs and rodents have a superior sense of smell overall, however a 2017 paper disputed that, saying that "the absolute number of

olfactory neurons is remarkably consistent across mammals".[9]

See also

References

  1. ^ Lin, S (1977). "Tastes and Odors in Water Supplies - A Review" (PDF). Department of Registration and Education. 127: 1.
  2. ^ L.J. van Gemert (2003) Flavour thresholds
  3. ^ a b c d Leffingwell & Associates. "Odor & Flavor Detection Thresholds in Water (In Parts per Billion)". Retrieved May 10, 2022.
  4. ^ PSabine, Widder; Symrise GmbH & Co. KG. "8-tetradecenal as fragrance and flavoring substance". Google Patents. Retrieved July 20, 2017.
  5. doi:10.1093/chemse/17.1.23
    .
  6. doi:10.1111/j.1365-2621.1999.tb15059.x
  7. PMID 24302690
    .
  8. PMID 28638852
    .
  9. TheGuardian.com
    . May 11, 2017.
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