5- Octen-2-one

Many problems associated with successfully identifying and simulating the flavors characteristic of conventionally baked foods have yet to be overcome in the development of new microwave products. This study addresses these problems by identifying compounds most important to the characteristic flavors of white cake batter, microwave and conventionally baked cake. Gas chromatography, mass spectrometry, and odor analysis by sniffing indicated that compounds such as diacetyl, C4-C10 aldehydes, C4-C10 alcohols, C8-C11 dienals, 3-octen-2-one, and 7-octen-4-ol were common to all three flavor systems. Conventional cake was found to contain higher levels of isopentenal and furfural than microwave cake. 

Ethynyl caibinols on heating with formic acid are isomerized to olefinic ketones for example, isohexylmethylethynylcarbinol is taken to 3,7-dimethyl-3-octen-2-one (48%) and 1-ethynyl-1-cyclohexanol to 1-acety 1-1-cyclohexene (70%). Small amounts of unsaturated aldehydes may contaminate the product. 

Figure 4. Testosterone concentration (ng/ml) in temporal gland secretion and relative abundance of four groups (I-IV) of compounds present in TGS over the course of musth in Tunga, an Asian bull elephant (a different elephant from the previous figures). Group I cyclohexanone, benzoic acid, phenylacetic acid, phenylpropanoic acid, octanoic acid, 3-octen-2-one and4-n-nonylphenol. Group II 5-nonanol, 2-hydroxyacetophenone, 1,3 dihydro-2H-indol-2-one, 2-nonanone, unidentified and 3-nonen-2-one. Group III phenol, decanoic acid and famesol. Group IV 4-hexenoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid and dotriacontanol.

Figure 2 illustrates the experimental setup employed for in vivo and in vitro flower scent sampling and the chromatographic profiles (total ion current) obtained. A total of 40 compounds were identified in Sansevieria trifasdata flower scent and their relative amounts changed during the day. There is no single, dominant component of the scent. Aldehydes (hexanal, heptanal, heptenal, nonanal, octenal, nonadienal, decanal), alcohols, ketones (6-methyl-5-hepten-2-one, 3-octen-2-one), acetates (benzyl, hexyl, octyl, 2-ethyl-l-hexyl, decenyl, decyl, dodecenyl, dodecyl and tetradecenyl), methyl and benzyl benzoate, methyl salicilate, eugenol, and ds,frflns-a-farnesene, were identified as the main scent constituents. 

Volatile decomposition products from autoxidized linoleic acid and methyl linoleate were characterized for their intense aroma and flavor impact by capillary gas chromatography-olfactometry. This technique involves sniffing the gas chromatograph effluent after stepwise dilution of the volatile extract. The most intense volatiles included hexanal, c/ -2-octenal, /ra. s-2-nonenal, l-octene-3-one, 3-octene-2-one and trans-l-ociQmX (Table 4.2). This analytical approach does not, however, consider the effects of complex interactions of volatiles occurring in mixtures produced in oxidized food lipids. 

The hydroperoxy epidioxides formed from photosensitized oxidized methyl linoleate are important precursors of volatile compounds, which are similar to those formed from the corresponding monohydroperoxides. Thus, 13-hydroperoxy-10,12-epidioxy-tra 5 -8-enoic acid produces hexanal and methyl lO-oxo-8-decenoate as major volatiles (Figure 4.24). The 9-hydroperoxy-10,12-epidioxy-rrans-13-enoic acid produces 2-heptenal and methyl 9-oxononanoate. Other minor volatile products include two volatiles common to those formed from the monohydroperoxides, pentane and methyl octanoate, and two that are unique, 2-heptanone and 3-octene-2-one. The hydroperoxy epidioxides formed from autoxidized methyl linolenate produce the volatiles expected from the cleavage reactions of linolenate hydroperoxides, and significant amounts of the unique compound 3,5-octadiene-2-one. This vinyl ketone has a low threshold value or minimum detectable level, and may contribute to the flavor impact of fats containing oxidized linolenate (Chapter 5). 

A mixture of acetyl chloride, AICI3, and methylene chloride stirred briefly under Ng, rran -l-hexenylmercuric chloride added, while backflushing with stirred 5 min. rran.y-3-octen-2-one. Y 97%. F. e. s. R. C. Larock and J. C. Bernhardt, Tetrah. Let. 1976, 3097. 

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