Acetic acid vanilla

White Or very slightly yellow needles pleasant aromatic vanilla odor and taste. Slowly oxidizes somewhat on exposure to moist air. Affected by light, d 1.056 mp 80-81 (81 -83 ) bp 285 bp,j 170°. One gram dissolves in 100 ml water. 16 ml water at 80s, about 20 ml glycerol freely so] in ale, chloroform, ether, carbon disulfide, glacial acetic acid, pyridine also sol in oils and aq solns of alkali hydroxides-Solns are acid to litmus. Preserve in tight, light-resistant containers. LDjo orally in rats 1580 mg/kg (Jenner). 

Formaldehyde is probably the best-known carbonyl compound. Large quantities are made into polymers such as Bakelite, Formica, and Melmac. Since formaldehyde has been cited as a probable carcinogen, its use in preserving biological specimens has virtually vanished. Acetaldehyde (ethanal) is used in manufacturing organic compounds such as acetic acid and ethyl acetate. Other aldehydes you have probably encountered are benzaldehyde (almond flavor), cinnamaldehyde (cinnamon flavor), and vanillin (vanilla flavor) (Fig. 21.26). 

Vanilla contains vanillin (1.3-3.0%) as the major flavor component, with over 150 other aroma chemicals also present, most of which are present in traces, including p-hydroxy-benzaldehyde, acetic acid, isobutyric acid, caproic acid, eugenol, furfural, p-hydroxy-benzyl methyl ether, vanillyl ethyl ether, anisyl ethyl ether, and acetaldehyde. The vanillin content differs in different varieties of vanilla, with Bourbon beans containing generally higher amounts than Mexican and Tahiti beans (martindale rosengarten stake). 

Vanilla flavour is not only determined and characterised by the vanillin molecule, but also by many more phenolic compounds and vanillin derivatives. Two examples of molecules that recently obtained FEMA-GRAS status are vanillyl ethyl ether and vanillin 2,3-butanediol acetal (Scheme 13.11). Vanillin can be hydrogenated to form vanillyl alcohol, which is also used in vanilla flavours. Vanillyl alcohol can be reacted with ethanol to form vanillyl ethyl ether. Vanillin can also form an acetal with 2,3-butanediol (obtained by fermentation of sugars) catalysed byp-toluene sulfonic acid in toluene. 

Figure 11 Expansion of the vanilla extract GCxGC-ToF MS chromatogram of the critical propylene glycol region (top) total ion chromatogram and (bottom) combined reconstructed ion chromatograms of m/z 73, 122, and 164 [25]. Peak assignment (5) benzoic acid ethyl ester (6) 2-methylbutanoic acid (7) pentanoic acid (8) 2-phenylethyl acetate.

Undecylenic acid n-Valeraldehyde Valeraldehyde hexyleneglycol acetal n-Valeric acid y-Valerolactone Vanilla (Vanilla planifolia) tincture Veratraldehyde Verdyl acetate p-Vinylphenol 2,3-Xylenol 2,5-Xylenol 2,6-Xylenol Zingerone fragrance, cough drops Menthol... 

Similar results have been obtained in a study of the biogenesis of vanillin (105) in Vanilla planifolia and a similar direct breakdown of the phenylpropanoid precursor ferulic acid (13) was proposed. The mechanism of breakdown of the cinnamic acids to Cg.Ci compounds has most reasonably been formulated by Zenk as a i -oxidation involving the removal of acetate (or more probably acetyl co-enzyme A) from the side chain of the phenylpropanoid substrate. A scheme based on these ideas is shown in Figure 5.11. 

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