Headspace volatiles

When a comparative analysis of the headspace volatiles of living and picked osmanthus flowers was performed by the dynamic headspace trapping method using Tenax GC, even more dramatic differences were observed, shown in Table 20 (60). 

It is interesting to compare data for headspace volatiles of the living vs picked and both of these with respect to the direct analysis of the extracts shown ia Table 19. 

Table 38. Comparison of Components of Authentic Coriander Seed Oil and Headspace Volatiles over Freshly Crushed Ripe Coriander Seeds ...

Table 41. Comparison of the Differences Between the Headspace Volatiles of Fresh Ginger Rhizome and a Commercial Oil ...

Juniper Oil. The best juniper oil [8012-91 -7] is obtained from the steam distillation of the ripe cmshed, dried berries of Juniperus communis L., a shmb which grows wild in many regions of Europe, Asia, Africa, and North America. However, most commercial juniperberry oil comes from the fermented fmits as a by-product of flavors for alcohoHc beverages such as gin, brandy, Hquors, cordials, and sloe-gin. This represents the actual commercial juniperberry oil, since very Httle tme juniperberry oil is produced. A comparison of the headspace volatiles of ripe juniperberries (85) with an authentic, freshly prepared juniperberry oil (86) is shown in Table 42. 

Table 42. Comparison of Headspace Volatiles of Ripe Juniperberries with an Authentic Juniperberry Oil...

Pimento Berry Oil. The pimento or allspice tree, Pimenta dioca L. (syn. P. officinalis, Liadl.), a native of the West Indies and Central America, yields two essential oils of commercial importance pimento berry oil and pimenta leaf oil. The leaf oil finds some use ia perfumery for its resemblance to clove leaf and cinnamon leaf oils as a result of its high content of eugenol. Pimento berry oil is an item of commerce with extensive appHcation by the flavor industry ia food products such as meat sauces, sausages, and pickles, and moderate use ia perfumery, where it is used primarily as a modifier ia the modem spicy types of men s fragrances. The oil is steam-distilled from dried, cmshed, fully grown but unripe fmits. It is a pale yellow Hquid with a warm-spicy, sweet odor with a fresh, clean topnote, a tenacious, sweet-balsamic-spicy body, and a tea-like undertone. A comparative analysis of the headspace volatiles of ripe pimento berries and a commercial oil has been performed and differences are shown ia Table 52 (95). 

Table 54. Comparison of Headspace Volatiles of Living Salvia officinalis and Commercial Sage Oil, Dalmatian ...

The headspace volatiles from biological fluids are comprised of a chemically diverse group of substances of widely different polarity most are alcohols, ketones, aldehydes, O- and M-hetrocyclic cosqpounds, isocyanates, sulfides, and hydrocarbons containing from 1 to 12 carbon atoms and with boiling points generally less than 300 C [342]. Quantitative differences in... 

More recently, solid phase microextraction (SPME) [22] has been applied to the analysis of bug pheromones, using two techniques. In the first, headspace volatiles are trapped on the SPME fiber, analogous to trapping on SuperQ [e.g., 23]. Alternatively, if the source of the pheromone is known, the SPME fiber can be wiped on the cuticle to directly adsorb the compounds [24]. In either case, the fiber is then thermally desorbed directly into a GC or GC-MS. Whereas this method is excellent for analysis, with good recoveries, it does not provide a sample that can be used for bioassays or for isolation of an active compound. 

Fig 1. Apparatus for collection of headspace volatiles from slurry A Large O-ring tap. 

Fig 5. TIC trace of headspace volatiles obtained from undigested slurry analysed on a non-polar column. 

Chaintreau, A., Grade, A., and Munoz-Box, R. Detertrrinationof partition coefficients and quantification of headspace volatile compounds, Anal. Chem., 67(18) 3300-3304, 1995. 

Benzoic acid Headspace volatile Benzothiazole, 2-methyl LP° ° Benzothiazole LP° °... 

Phenylethyl alcohol, 2 Sh 0.1-0.13% Phenylethyl alcohol Headspace volatile ... 

Aronson, J. and Ebeler, S. E. (2004). Effect of polyphenol compounds on the headspace volatility of flavors. Am. J. Enol. Vitic. 55,13-21. 

Giri, A., Osako, K., and Ohshima, T. (2010a). Identification and characterization of headspace volatiles of fish miso, a Japanese fish meat based fermented paste, with special emphasis on effect of fish species and meat washing. Food Chem. 120, 621-631. 

Figure 10.25 GC-MS chromatograms of the headspace volatiles of six cheese varieties (from...

Equilibrium of headspace volatile lipids is influenced by a number of factors including the solubility of the component in the food matrix and the vapor pressure over the food system. This relationship may be very complex and must be determined experimentally by spiking the sample with known quantities of the compound of interest and subtracting background levels (Reineccius, 1993). 

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