Odor perception test

Whatever the physiology of odor perception may be, the sense of smell is keener than that of taste (22). If flavors are classed into odors and tastes as is common practice in science, it can be calculated that there are probably more than 10 possible sensations of odor and only a few, perhaps five, sensations of taste (13,21,35—37). Just as a hereditary or genetic factor may cause taste variations between individuals toward phenylthiourea, a similar factor may be in operation with odor. The odor of the steroid androsterone, found in many foods and human sweat, may eflcit different responses from different individuals. Some are very sensitive to it and find it unpleasant. To others, who are less sensitive to it, it has a musk or sandalwood-like smell. Approximately 50% of the adults tested cannot detect any odor even at extremely high concentrations. It is befleved that this abiUty is genetically determined (38). 

Brown-DeGane AM, McGlone J Multiple chemical sensitivity a test of the olfactory-limbic model. J Occup Environ Med 41 366-377, 1999 Caccappolo E, Kipen H, Kelly-McNeil K, et al Odor perception multiple chemical sensitivities, chronic fatigue, and asthma. J Occup Environ Med 42 629-638, 2000 Cone JE, Harrison R, Reiter R Patients with multiple chemical sensitivities clinical diagnostic subsets among an occupational health clinic population. Occup Med 2 721-738, 1987... 

The use of the senses of taste and smell are subject to restrictive limitations. First of all they are not precise. Various opinions on the numerical difference in the intensity of odors that an individual can distinguish give a range from 30% to well over 100%. Another limitation inherent in any test based on odor perception is imposed by the rapid onset of fatigue the sense of smell quickly becomes dulled. Various views exist as to the period of time over which reliable data on odor can be obtained. Much depends on the testing procedure, but even with the most favorable circumstances the maximum time is probably less than an hour. The permissible time is very brief when dealing with odors that have anesthetic effect on odor-perception. 

Usually it is feasible to determine the approximate relative efficiency of two, or even three, carbons within the allowable time for conducting a test on odor, but when more carbons are to be evaluated the odor-perception will probably be dulled before the testing can be completed. Therefore, when many carbons are to be evaluated, the study should be subdivided and conducted in separate sessions, using two carbons at each session. 

Besides the differences in odor perception, preliminary biodegradation tests show that the two natural (4/ )-enantiomers (5, 6) were biodegraded 90% within 28 days, compared with no biodegradation of the (4S)-enantiomers (7, 8). In further studies, the biodegradation of the (47 )-cis isomer 5 is much more facile than that of the (47 )-trans isomer 6. 

The diversity of human olfactory acuity, as defined by specific anosmia, may be caused by the diversity of the olfactory receptor protein repertoire in humans. Physiologically, humans have a limited number of clearly defined olfactory receptor types that modulate odor perception in response to a small recurrent set of odorants distributed throughout the natural world. For example, the Flavornet lists about 500 chemicals reported to be above their threshold in natural products [39,40]. Natural products contain a subset of functional odorants, above their threshold, that invoke perceptions that humans experience as odor. The same odorants are found in many natural products but in different relative concentrations. Tested individually, these odorants produce precepts that have been... 

The gravitational field affects olfaction as it does vision, audition, or vestibular function. It could impair detection of dangerous fumes or burning electrical equipment in airplanes or space vehicles. Astronauts also report altered perception of food flavors under weightless conditions. Men and women tested with four scratch-and-sniff odor samples of the University of Pennsylvania Smell Identification Test identified odors more poorly when in an upside-down position (Mester eta/., 1988). 

Chlorates. — On warming 2 gm. of powdered barium chloride with 10 cc. of concentrated hydrochloric acid iii a test tube, neither the crystals nor the liquid should acquire a yellow color nor should the odor of chlorine become perceptible. 

ORGANOLEPTIC. A term widely used to describe consumer testing procedures for food products, perfumes, wines, and the like in which samples of various products, flavors, etc. are submitted to groups or panels. Such tests are a valuable aid in determining the acceptance of tlie products and thns may be viewed as a marketing technique, They also serve psychological purposes and are an important means of e valuating the subjective aspects of taste, odor, color, and related factors, The physical and chemical characteristics of foods are stimuli for the eye, ear, skin, nose, and mouth, whose receptors initiate impulses that travel to the brain, where perception occurs. 

Assay Dissolve about 1 g of sample, accurately weighed, in 50 mL of water, add 50.0 mL of 0.05 M disodium EDTA and 20 mL of pH 4.5 buffer solution (77.1 g of ammonium acetate and 57 mL of glacial acetic acid in 1000 mL of aqueous solution), and boil gently for 5 min. Cool, and add 50 mL of alcohol and 2 mL of dithizone TS. Back titrate with 0.05 M zinc sulfate to a bright rose-pink color. Perform a blank determination (see General Provisions), and make any necessary correction. The milliliters of 0.05 M disodium EDTA consumed is equivalent to 50 minus the milliliters of 0.05 M zinc sulfate used. Each milliliter of 0.05 M disodium EDTA is equivalent to 23.72 mg of A1K(S04)2T2H20. Ammonium Salts Add 1 g of sample to 10 mL of 1 N sodium hydroxide in a small beaker, and heat on a steam bath for 1 min. The odor of ammonia is not perceptible. Fluoride Determine as directed in Method V under Fluoride Limit Test, Appendix IIIB. 

Ammonia Heat 500 mg of sample with 5 mL of 1 N sodium hydroxide. The odor of ammonia is not perceptible. Chloride Heat 1 g of sample with 25 mL of water and 2 mL of nitric acid until the sample dissolves. Cool, dilute with water to 100 mL, and mix. Add 1 mL of silver nitrate TS to 10 mL of the solution. No turbidity immediately develops. Lead Determine as directed in the Flame Atomic Absorption Spectrophotometric Method under Lead Limit Test, Appendix IIIB, using a 1-g sample. 

The softener performance perceived by consumers is the balance between the absolute efficacy determined in the laboratory and the product aesthetics. In other words, the consumer perception of the product performance is heavily influenced by aesthetic attributes such as fragrance and viscosity. Consumer tests indeed show that perfume, and more precisely perfume substantivity on fabrics, is the main reason for preferring one product among several delivering the same softness. Consumers appreciate both the odor of the product itself, which generates the appeal and causes the purchase intent, and the smell of the laundered fabrics, which settles the repurchase intent. 

A convenient test which may be used to detect small quantities of formaldehyde is made as follows To about one cubic centimeter of the solution of the aldehyde, which has been diluted to such a concentration that its odor is barely perceptible, is added one drop of a one-half per cent aqueous solution of resorcinol (534). The mixture so prepared is poured slowly down the side of a test-tube containing about 5 cc. of concentrated sulphuric acid in such a way that the two liquids do not mix. A red ring soon appears at the juncture of the two liquids, and a white flocculent precipitate, which changes to red, forms in the aqueous layer. 

Dimethyl sulfate (CAS 77-78-1) Powerful vesicant action hydrolyzes to sulturic acid and methanol. Extremely irritating upon direct contact severe bums have resulted. Vapors irritating to eyes and respiratory tract delayed pulmonary edema may result. Skin absorption is rapid. A carcinogen in test animals (lARC 2A). 0.1 ppm, S,A3 7 ppm 4 2 0 Colorless, oily liquid. Very mild onion odor is barely perceptible and Is a poor warning property. Vapor pressure is 0.5 mm Hg at 20°C (68°F). Combustible. Thermal-breakdown products Include sulfur oxides. 

The odorant concentrations remained within the relative unit ranges tested in the actual experiment. The sensory attributes could act as constraints. For instance, one goal was determination of the optimum acceptability level, with the perception of overall odor intensity lying between prescribed limits of intensity. 

Linear equations conveniently summarize how concentrations of odor components relate to the mixture intensity of specific characteristics. Given the component concentrations, even at intermediate, non-tested levels, one can estimate the profile of perceptions expected from that mixture by using the equations in Table VIA-VID. 

In the present study chemosensory event-related potentials (CSERP) were used to find objective evidence that body odor and the perception of body odor by females is related to the similarity of the Major Histocompatibility Complex (HLA in humans) of the subject and donor. Ten female subjects were examined three times during the course of their menstrual cycle (follicular, ovulatory and luteal phase). During a test session the responses of subjects to the odors of either three male or three female donors was measured. The HLA types of two donors were similar to each other but different to the HLA type of the test subject and the third donor, who shared a similar HLA type. Chemosensory event-related potentials were recorded from 7 electrode sites on the skull (Fz, Cz, Pz, F3, F4, P3, P4), referred to linked mastoids. Preliminary results show that during the ovulatory cycle phase, subjects responded with larger amplitudes to body odors of male donors with a similar HLA-type than to odors of male donors with a dissimilar HLA-type. When female odors were presented the speed of the neural response changed with the HLA-type of the odor donor during the luteal phase only. 

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