Terpene Sulfur Compounds

The chemical is used both in flavours and fragrances, but owing to its very strong smell and low odour threshold value the volume is limited. 

Pulegone is the major constituent of pennyroyal oil from Mentha pulegium L., which is available in large quantities. 

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The modern distinction between vegetable and fruit has been applied and therefore those plants or plant parts that are usually consumed with the main course of a meal will be regarded as vegetables thus, cucumber, tomato and pumpkin that botanically are classified as fruits are included in this section. The flavour compounds found in vegetables are diverse and include fatty acid derivatives, terpenes, sulfur compounds as well as alkaloids. This diversity is partially responsible for the unique flavours found in different species of vegetables. 

Cysteine can be obtained by hydrolysis from cysteine-rich proteins in hair or feathers or from petrochemical sources. Cysteine is an important raw material in Maillard reactions for the preparation of process flavours, but it can also serve as a source of ammonia and hydrogen sulfide for the preparation of flavour chemicals, such as the terpene sulfur compounds mentioned in Sect. 13.2.4 and furfuryl mercaptan mentioned in Sect. 13.4.2.4. 

Organic sulfur compounds such as sulfurized spermaceti oil, terpene sulfides, and aromatic disulfides have been used. Encumbered phenols such as di-tertiary-butylphenols and amines of the phenyl-alphanaphthylamine type are effective stopping the kinetic oxidation chain by creating stable radicals. 

A mammal may emit many volatile compounds. Humans, for instance, give off hundreds of volatiles, many of them chemically identified (Ellin etal., 1974). The volatiles include many classes of compound such as acids (gerbil), ketones, lactones, sulfides (golden hamster), phenolics (beaver, elephant), acetates (mouse), terpenes (elephant), butyrate esters (tamarins), among others. The human samples mentioned before contained hydrocarbons, unsaturated hydrocarbons, alcohols, acids, ketones, aldehydes, esters, nitriles, aromatics, heterocyclics, sulfur compounds, ethers, and halogenated hydrocarbons. Sulfur compounds are found in carnivores, such as foxes, coyotes, or mustelids. The major volatile compound in urine of female coyotes, Canis latrans, is methyl 3-methylhut-3-enyl sulfide, which accounts for at least 50% of all urinary volatiles (Schultz etal, 1988). 

Turpentine oils extracted from pine resins are now marginal sources of terpenes pinenes, carene and some other monoterpenes are essentially obtained from the paper oils produced in the KRAFT process. Nevertheless this process is based on a treatment of wood chips in sodium sulfide, which leaves significant fractions of sulfur compounds in the paper oils. For the use of terpenes, these sulfur compounds must be eliminated. The process requires ... 

VOCs responsible for the smell of brand new cars alkanes, aromatic hydrocarbons, carbonyl compounds, residual monomers, alcohols, esters, ethers, halo-genated hydrocarbons, terpenes, nitrogen and sulfur compounds ... 

Natural food flavors such as terpenes, hydrocarbons, alcohols, aldehydes, ketones, esters, acids, lactones, amines, sulfur compounds are enzymatically produced in fruits and vegetables. On the contrary, processed food develops its characteristic acceptable flavors from chemical reactions within its components at temperatures far below those at which its major components, i.e., lipids, proteins and carbohydrates pyrolyze. 

Tobacco leaf has a complicated chemical composition including a variety of polymers and small molecules. The small molecules from tobacco belong to numerous classes of compounds such as hydrocarbons, terpenes, alcohols, phenols, acids, aldehydes, ketones, quinones, esters, nitriles, sulfur compounds, carbohydrates, amino acids, alkaloids, sterols, isoprenoids [48], Amadori compounds, etc. Some of these compounds were studied by pyrolysis techniques. One example of pyrolytic study is that of cuticular wax of tobacco leaf (green and aged), which was studied by Py-GC/MS [49]. By pyrolysis, some portion of cuticular wax may remain undecomposed. The undecomposed waxes consist of eicosyl tetradecanoate, docosyl octadecanoate, etc. The molecules detected in the wax pyrolysates include hydrocarbons (Cz to C34 with a maximum of occurrence of iso-Czi, normal C31 and anti-iso-C32), alcohols (docosanol, eicosanol), acids (hexadecanoic, hexadecenoic, octadecanoic, etc ). The cuticular wax also contains terpenoids such as a- and p-8,13-duvatriene-1,3-diols. By pyrolysis, some of these compounds are not decomposed and others generate closely related products such as seco-cembranoids (5-isopropyl-8,12-dimethyl-3E,8E,12E,14-pentadecatrien-2-one, 3,7,13-trimethyl-10-isopropyl-2,6,11,13-tetradecatrien-1al) and manols. By pyrolysis, c/s-abienol, (12-Z)- -12,14-dien-8a-ol, generates mainly frans-neo-abienol. 

Terpenes Ammonia NII3) Hydrogen cyanide (HCN) Acetonitrile (CHcCN) Cyanogen (NCCN) Amines, heterocydes, amino acids Methyl chloride CH3CI) Sulfur compounds (lLS,COS, DMS,DMDS) Aerosols (4 wt % Soot) Nitrogen (N,) Cyanogen (NCCN) Sulfur dioxide (SO,) Aerosols (40 wt % Soot) ... 

Using this method 29 higher alcohols, 11 aldehydes, 16 organic acids, 18 ketones, 58 esters, 9 phenols, 12 furans, 26 terpenes, 4 sulfuric compounds, 5 hydrocarbons, 2 lactones, 2 pyrans and 15 others compounds were identified. In total, 207 volatile compounds were found. The higher alcohols had the high concentration and the esters were the most diverse compounds... 

The primary aromatic substances in beer are derived from raw materials (barley or hops) that confer the beer s typical odour and taste. Bitter acids of hops have a bitter taste (see Section 8.3.5.1.3), but hop cones also contain 0.3-1% m/m of terpenoids (60-80% of hop essential oil), which have a considerable influence on the smell of beer. The main components of aromatic hop oils are sesquiterpenic hydrocarbons in which a-humulene, P-caryophyllene and famesene dominate. The major monoter-penic hydrocarbon is myrcene. For example, the essential oil content of fine aromatic varieties, such as Saaz, is 0.8% m/m, of which 23% is myrcene, 20.5% a-humulene, 14% famesene 6% and P-caryophyUene. Significant components of the hop aroma in beer are mainly isomeric terpenoid monoepoxides resulting from autoxidation and diepoxides of a-humulene and fS-caryophyUene, but also other terpenoids. Important components of hops odour are also various alcohols (such as geraniol and hnalool), esters (ethyl 2-methylpropanoate, methyl 2-methylbutanoate, propyl 2-methylbutanoate and esters of terpenic alcohols, such as geranyl isobutanoate), hydrocarbons, aldehydes and ketones formed by oxidation of fatty acids, such as (3E,5Z)-undeca-l,3,5-triene, (Z)-hex-3-enal, nonanal, (Z)-octa-l,5-dien-3-one, their epoxides, such as ( )-4,5-epoxydec-2-enal and sulfur compounds. Other important components of hops are so-called polyphenols (condensed tannins) that influence the beer s taste and have antioxidant effects. Less important compounds are waxes and other hpids. Hop products, such as powder, pellets and extracts (by extraction with carbon... 

Putrefied animal matter hcis formed the basis for coyote attractants of possible value in pest control programs. Thus, a putrefied fish formulation has been used as a coyote lure and, more recently, attention has been directed to a fermented aqueous suspension of chicken whole-egg powder, developed initially as an attractant for flies (48). The odor components csf this material have been subjected to detailed chemical analysis ty Bullard et al. (49) and are reported to include volatile fatty acids (77% total 13 acids identified), bases (13% total, mainly trimethylamine, 9 amines identified), and headspace volatiles, including esters, aldehydes, ketones, alcohols, alkyl aromatics, terpenes and sulfur compounds (10% total, 76 compounds identified). Based on these data, a synthetic mixture, "synthetic fermented egg" has been formulated, composed largely of a mixture of ten volatile fatty acids (81%), together with a diverse range of amines and other compounds (50). This mixture was found to be as attractive to coyotes as the fermented preparation itself. The volatile fatty acid component alone was found to exhibit substantial coyote attractancy also (50,51). ... 

Of the few known terpene compounds that contain heteroatoms such as nitrogen or sulfur, the thiol 8-mercapto-p-menthan-3-one described below has qualitatively important applications as a fragrance and flavor substance. The second thiol, -p-menthene-8-thiol, is described because its odor threshold value is far lower than that of most other fragrance and flavor materials. 

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