Odor spectrum value

Odor spectrum value OSV. Normalized odor data taken from each peak of the chromatogram that has been adjusted for odor compression using Stephen s Law (Acree, 1997 Ong et al., 1998). The odor chromatogram is redrawn as an odor spectrum. An odor spectrum value can be determined for each odorant in the sample. The values are independent of the method used for collecting odor data and of the concentration, and convey the relative importance of each odorant in the sample. 

The dynamic range of OSME and GC-SNIFF data is generally less than a factor of ten, whereas dilution analysis frequently yields data that cover three or four powers of ten. It has been determined, however, that compressive transforms (log, root 0.5, and so on) of dilution analysis data are needed to produce statistics with normally distributed error (Acree and Barnard, 1994). Odor Spectrum Values (OSVs) were designed to transform dilution analysis data, odor units, or any potency data into normalized values that are comparable from study to study and are appropriate for normal statistics. The OSV is determined from the equation ... 

TABLE 2.1 Average odor spectrum values of the active odorant compound in Amontillado wines.0 Reprinted with permission from Moyano et al. (2010). Copyright 2010. American Chemical Society. 

IRMS LC MDGC MS MSA NIF NMR OAV OSV PCA RAS RP SDE SFE SIM SNIF SPME TIC TLC Stable Isotope Ratio Mass Spectrometry Liquid Chromatography MultiDimensional Gas Chromatography Mass Spectrometry Multivariate Sensory Analysis Nasal Impact Frequency Nuclear Magnetic Resonance spectroscopy Odor Activity value Odor Spectrum Value Principal Component Analysis Retronasal Stimulation Reversed Phase Simultaneous steam Distillation Extraction Supercritical Fluid Extraction Selected Ion Monitoring Surface of Nasal Impact Frequency Solid Phase Micro Extraction Total Ion Current Thin Layer Chromatography... 

Aroma activities of volatile compounds obtained by GCO dilution analyses were represented as Charm values, and the relative intensities of component odorants were represented in terms of the odor spectrum value (OSV) [14]. Each Charm value was rounded off to two significant figures in order to reflect the actual resolution of the dilution analysis. Acidic, buttery-oily, green-black currant, green-earthy, nutty-roast, phenolic, smoke-roast, soy sauce, sweet-caramel, and sweet-fruity were the aroma descriptions used in all GCO experiments to describe potent odorants. These descriptions were chosen from the results of a single preliminary free choice GCO analysis using a lexicon of words commonly used for coffee evaluation. 

Odor spectrum value (OSV) is the normalized Charm value modified with an approximate Stevens s law exponent ( = 0.5). 

Table 4 Potent Odorants (Above 50% Odor Spectrum Value) Found in the Headspace Volatiles of Roasted Coffee Beans Using the Dynamic Solid-Phase Microextraction Sampling Method...

Figure 8 Two-dimensional scatter plots of the factor loading (A) and principal component score (B) using the total Charm values of 10 aroma descriptions (above 50% OSV). E, Ethiopia T, Tanzania I, Indonesia. Numbers (26, 23, and 18) refer to roast degrees. OSV, odor spectrum value.

To obtain responses closer to the perceived odor intensities, Friedrich and Acree proposed the transformation of the CharmAnalysis or OAV into an odor spectrum using Stevens law (9,10). However, a median value of 0.5 was used as a Stevens exponent, whereas this number may vary significantly from one compound to another [e.g., 0.24 for guaiacol (23)]. 

Yellow monoclinic prisms from water Or petr ether. Penetrating odor resembling that of chlorine. Irritating vapors, dj 1.318. mp 115.7. Sublimes [sublimation velocities is vacuo Kempf, J. Praia. Chem. [2] 78, 236 (1908)], Volatile with steam. Absorption spectrum Hantzsch, Ber. 49, 522 (1916). Dipole moment 0,67. Polemic Over correct values Paoloni, J. Am. Chem. Soc, 00, 3879 (1958). Slightly sol in water sol in alcohol, ether, hot petr ether, alkalies. LDW orally in rats 130 mg/kg, Woodard et al. Fed. Proc. 8, 348 (1949). 

Purification and Characterization. No further purification of the product is usually necessary. Note the hyacinth-like odor of the liquid. Determine the refractive index and compare it to the literature value (lit. value = 1.6070 at 20 °C, 78% trans isomer). Obtain IR and NMR spectra of the oil. In the infrared, the cis isomer shows a phenyl C—H bend at 770 cm , while the trans isomer shows this bending mode at 731 and the alkene C—H out-of-plane mode is found at 941 cm (see Bibliography, Strom et al.). Compare your results with the spectrum recorded in the literature The Aldrich Library ofIR Spectra and/or SciFinder Scholar). 

As in the case of the deoxyosones, the concentrations of Amadori and Heyns compounds vary, depending on the reaction conditions (pH value, temperature, time, type and concentration of the educts). As a result, there is a change in the product spectrum and, consequently, in the color, taste, odor, and other properties of the food in each case. 

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