Odor sweaty

Enantiomers of the same compound may have differing threshold values. This property was observed for a new, strong and high impact, flavor compound, 3-thio-2-methylpentan-l-ol, first detected in thermally processed materials but that is actually present in raw onions.54 First of all, there is a marked concentration effect at 1 ppm in 5% saltwater, the odor is described as sulfuric, burnt gum, sweaty, onion and at 0.5 ppb as meat broth, sweaty, onion, leek . Since there are two chiral centers (both dependent on carbon) there are four stereoisomers, all of which have been prepared 18a, 18b, 19a, 19b (Scheme 7). For this compound, enantiomers have the following marked differences in odor thresholds (but apparently all have the same general odor). 

Neonate fulminant syndrome coma, convulsions. Rancid odor of sweaty socks ... 

Here is a bit of a complication there is a lot of individual variation in the sense of human olfaction. Not everything smells the same to everyone. This holds both for the intensity of the perceived smeU as well as for its quality pleasant, floral, skunky, sweaty, or no odor at all. Andreas Keller has recently demonstrated that some significant part of this individual variation in the sense of smell derives from genetic variation in human odorant genes. Specifically, two single nucleotide polymorphisms (SNPs), leading to two amino acid substitutions in an odorant receptor, have dramatic affects on the perception of the odor of androstenone, a steroid derived from testosterone. 

Preschool children are reputed to differ from adults in their odor preferences. For instance children aged 3-4 years were as likely to like the odor of amyl acetate (banana) as synthetic sweat or feces odors. By 6 years of age, their preferences resembled adults, liking banana, and disliking sweaty and fecal odors (Stein et al., 1958). At 4-5 years of age, a shift occurs from positive or neutral to negative characterization of odors of sweat, feces, asa foetida, or butyric acid. However, it is increasingly becoming clear that responses by very young children... 

For most specific anosmias the individual differences represent a concentration effect that is anosmic individuals will recognize the odor at some higher level of exposure. However, in the case of an stenone, individuals d it either unpleasant (urinous, sweaty), pleasant (floral, musky) or odorless, independent of the concentration. Surprisingly, the anosmia can be reversed in some individuals through constant exposure (57). Anosmic subjects exposed to androstenone three times per day (3 minutes) over a 6 week period became osmic to it A substantial decrease in threshold (i.e. increased sensitivity) was found for 10 of 20 subjects. 

Isovaleric acidemia. This is believed to be a defect in the step from isovaleryl Co A to beta-methyl cro-tonyl Co A, in the metabolism of leucine. Rather than a maple syrup odor, there is an odor of sweaty feet . The patient has various neurologic disturbances and mental retardation. Isovaleric acid is elevated in the plasma. It is treated by restricting dietary intake of leucine. 

Episodic vomiting, lethargy, coma, sweaty feet odor... 

Compared to emmental cheese, the aroma of gruyere cheese is more intensely sweaty and less caramel-like [55]. The composition of the key odorants reflects these differences as the concentrations of the caramel-like smelling furanones are lower and that of methylbutyric acid is higher [57, 58[. 

Although copper possesses no odor, it does conjer upon sweaty hands and water in which it has stood for a long time (as in copper alembics or kettles) a peculiar, unpleasant odor. 

Butanoic acid has a powerful, penetrating, diffusive sour odor, reminiscent of rancid butter (Arctander, 1967). It is in the list of potent odorants in raw arabica with a sweaty odor description (Czerny and Grosch, 2000). An odor threshold of 240 xg/l (0.24 ppm) in water is quoted by Teranishi (1971). A flavor threshold of 6.8 ppm in water is given by Patton (1964), and 6.2 ppm by Siek et al. (1969). 

It has a very powerful and penetrating, diffusive, acid odor, pungent when undiluted, but more unpleasant when diluted. In fact it becomes more animal- and perspiration-like in dilution. Only in extreme dilution does the odor become again more pleasant, fruity, warm. Below 10 ppm, the taste is rather fruity, but at higher concentrations, the odor develops and it becomes more unpleasant (Arctan-der, 1967). For Czerny and Grosch (2000), it is one of the potent odorants in green coffee with a sweaty odor description. 

This acid has a particularly pungent and acrid odor reminiscent of Roquefort cheese and of other cheeses. The taste is acrid-acid but becomes fruity-sour below 10 ppm (Arctander, 1967). By GC-olfactometry, the odor perception, in the evaluation of the aroma of a roasted Columbian coffee, is sweaty, fermented together with the 3-methyl isomer, the contribution to coffee flavor is very important (Holscher et al., 1990). In the aroma of a green coffee, it is described as weak, fermented (Holscher and Steinhart, 1995). Karl et al. (1992) showed that the enantiomers have different odors, the (R)-isomer being cheesy and the (5)-isomer fruity. 

This compound is very diffusive, acid-acrid in moderate dilution it has a cheesy, unpleasant odor. In extreme dilution the odor becomes more agreeable, herbaceous (Arctander, 1967). The odor perception by GC-olfactometry is strong, sweaty in roasted (Holscher et al., 1990) and green Columbian coffee (Holscher and Steinhart, 1995). Together with the 2-methyl isomer, it makes an important contribution in coffee flavor. 

According to the latter authors, the pure substance has a sweaty, fruity odor, becoming black currantlike and catty in aqueous solution (ca 0.1 ppm). The odor and taste thresholds, 2-5 and 5-8 ppt respectively, are nearly ten times higher than those of prenyl mercaptan (Q.10). This mercaptan... 

Fresh perspiration is odorless. Bacteria that are always present on our skin produce lactic acid, thereby creating an acidic environment that allows other bacteria to break down the components of perspiration, producing compounds with the unappealing odors we associate with armpits and sweaty feet. One such compound is butanedione. 

Figure 5. Peak number plots for the musty and sweaty odors, and for 15 standard odorants which represent a variety of unrelated odors, thereby showing at most only one marginally significant deviation from the number of peaks to be expected in any randomly selected group of unrelated...

These odors include spermous, musky, fishy, urinous, malty and sweaty, and can be related to some observed human odors (39). 

Thus, Amoore suggests that, if we have a specific olfactory receptor for a given odorant then that odorant might be naturally given off by the body. The sweaty odor of isovaleric acid is probably part of the foot odor and is produced by the action of skin bacteria on apocrine secretion (see below). Pyrolline, the spermous odor, has been shown to be produced by enzymatic breakdown of the polyamines in semen (40). Androst-16-en-3-one, the urinous primary odor, has axillary-like odor the related androstenol, which is found in urine, is perceived as a musky odor to some individuals (41). Both steroids are found in axillary sweat and may be formed as metabolites of apocrine secretion. Chemicals which fit the malty anosmia have not as yet been reported from human odor sources. The natural musks, such as cycloheptadecenone (civet), were first obtained from animal scent glands. 

Pierce, Jr., J. D., Zeng, X.-N., Aronov, E. V., Preti, G., and Wysocki, C. J., 1995, Cross-adaptation of sweaty-smelling 3-methyl-2-hexenoic acid by a structurally-similar, pleasant-smelling odorant, Chem. Senses 20 401-411. 

Poor feeding, vomiting, sweaty-feet body odor, seizures, coma, death if untreated... 

Properties Colorless gas R.T. readily liquefied fishy oily rancid sweaty odor saline taste sol. in water, alcohol, ether, benzene, toluene, xylene, chloroform, chlorinated and aromatic soivs. misc. with oxygenated soivs. m.w. 59.11 dens. 0.932 m.p. -117 C b.p. 2.9 C flash pt. 38 F ref. index 1.3443... 

Valeric acid (penta-noic acid) Fatty, earthy, putrid acidic, sweaty, cheesy odor, sharp, acidic, mUky cheese, slightly fruity. Megasphaera/Brettanomyces/Clostridium spps. 

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