Volatile compounds garlic

Self-Test 4.10B The Codex Ebers, an Egyptian medical papyrus, describes the use of garlic to treat many ailments, including the cleansing of wounds. Chemists today have discovered that the oxide of diallyl disulfide (the volatile compound responsible for garlic odor) is a powerful antibacterial agent more potent against typhoid than penicillin. At 177°C and 200 Torr, a sample of diallyl disulfide vapor has a density of 1.04 g-L 1. What is the molar mass of diallyl disulfide ... 

The analysis of natural compounds in foods is also assisted by the use of the purge and trap technique in methods for distinguishing strawberry varieties [100] the aroma of unprocessed foods including gherkin [101], durian [102], garlic [103] and meat [104-107] cheese [108,109] and other dairy products [110] tobacco, tea and coffee [111,112] and peanuts [112]. Food additives including sulphur dioxide [113,114] and food contaminants such as VOCs [115-126], have been recovered by PT, particularly from table-ready foods. Animal [127,128] and plant tissues [129,130] have also been subjected to PT for separation of volatile compounds. 

Kim, S.M. et al., Effect of soybean oil on garlic volatile compounds isolated by distillation, J. Agric. Food Chem., 43, 449, 1995. 

Yu, T.H., Wu, C.M., and Ho, C.T., Volatile compounds of deep-oil fried, microwave-heated, and oven-baked garlic slices, J. Agric. Food Chem., 41, 800, 1993. 

DHS applications have been developed, for example, for the determination of aroma-active compounds in bamboo shoots (83), styrene in yoghurt (8- ) and volatile acids in tobacco, tea, and coffee (88), volatile compounds of strawberries (89) and odor-active compounds of hams (90). The applications of DTD-GC include, for example, in the determination of volatile components of Lavandula luisieri (85), in the analysis of volatile components of oak wood (87) and volatiles in various solid-food products such as spices and herbs (black pepper, oregano, basil, garlic), coffee, roasted peanuts, candy and mushrooms (82). 

Tabic 1, Some imponani volatile compounds identified in garlic samples... 

For years researchers have investigated the sulfur compounds present in various foods. Cooked foods typically contain numerous sulfur compounds, especially heterocyclic compounds like thiazoles, thiophenes, thiazolines, etc. In 1986, Sha-hidi et al. (7) reported that 144 sulfur compounds had been identified in beef. Other heated food systems like bread, potato products, nuts, popcorn, and coffee also contain many sulfur compounds. Aliphatic thiols have been found in fruits, vegetables, dairy products etc., as well as in heated foods. No discussion of the occurrence of sulfur compounds in foods would be complete without mention of their major role in the various allium species. Indeed, more than half of the volatile compounds reported in garlic, onion, leek, and chive contain sulfur (2). Comprehensive reviews of the literature concerning the role of thiazoles, thiophenes, and thiols in food flavor through 1975 can be found in Maga s series of review articles (3-5). 

Alliin and deoxyalliin, two important nonvolatile flavor precursors of garlic, were reacted separately with inosine-5 -monophosphate (IMP) in an aqueous solution at pH 7.5 in a closed sample cylinder at 180 °C for one hour. The volatile compounds generated were isolated by using a modified Likens-Nickerson (L-N) distillation-solvent extraction apparatus, and analyzed by GC and GC-MS. 

Volatile compounds of garlic were collected using a Liken-Nickerson steam distillation and solvent extraction apparatus (Romer and Renner, 1974). The volatile compounds were determined using gas chromatography and then further examined by GC-MS. The... 

In conclusion, the conversion of AA by LAB generates a variety of aroma compounds, including branched-chain acids (cheesy) and aldehydes (malty), aromatic alcohols and aldehydes (floral), and volatile sulfur compounds (garlic, cabbage, boiled potato) (Table 19.1). The expression of LAB enzymes in situ is influenced by a number of factors detailed in Section 19.5. 

A tree, Scorodocarpus borneensis, native to Borneo and the Malay peninsula, has a garlic-like smell and is known as wood garlic . The fruit is used locally for seasoning. The major volatile flavor compounds from wood garlic are similar to those of garlic itself. Some of these materials are polysulfur compounds and have antimicrobial activity against some bacteria and fungi. These materials contain four sulfur atoms.75 They are either 2,4,6-trithiaheptane-5-thione-2,2-dioxide (CH3-SO2-CH2-S-CS-S-CH3) or derivatives of tetrathia-octane (CH3-S-CH2-S-S-CH2-S-CH 3, CH3-SO2-CH2-S-S-CH2-S-CH3, CH3-S-CH2-SO2-S-CH2-S-CH3). 

A number of volatile aliphatic compounds that contain nitrogen or sulfur atoms are important aroma constituents. Alkyl thiols, dialkyl sulfides and disulfides, and alkyl thiocyanates belong to this group. They occur widely in foods and spices and determine the odor of, for example, onions, garlic, and mustard. Because of their potent smell, they are used in high dilution and are often produced only in small quantities. The same is true for the following ... 

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