Flavors components

The main flavor component of the hazelnut is 2E 5S) 5 methyl 2 hepten 4 one Wnte a structural formula or build a molecular model showing its stereochemistry... 

Cinnamomum cassia B/um (Lauraceae) is the so-caUed cassia. It is native to southeastern China and has not been grown successfuUy outside of this area. The dried bark of this evergreen tree is stripped, ground, and sold almost exclusively in China. The leaves and twigs of the tree contain the same flavor components as the bark and are steam distUled to yield the cassia oil of commerce. Infrequently, smaU amounts of bark are bundled and exported as cassia lignea but caimot compete with the other varieties as bark spice. The Chinese prefer to seU the essential oil. 

Other botanical varieties are caUed cassia, but the leaves of these varieties differ in flavor components from those of the bark. Saigon cinnamon, C. loureirii Nees, from Viet Nam, closely resembles Chinese cassia in appearance but is grown on the other side of the mountains and has an entirely different flavor character, containing no orthomethoxy cinnamic aldehyde. C. burmani B/ume, ie, Korintje or Kerintje cinnamon and Padang or Batavia cinnamon, is from Sumatra and Indonesia. C. sintok B/ume is native to Malaysia and of minor commercial importance. 

There are two methods available for aroma recovery. In one method, a portion of the water is stripped from the juice prior to concentration and fractionally distilled to recover a concentrated aqueous essence solution. Apple juice requires 10% water removal, peach 40%, and Concord grape 25—30% to remove volatile flavor as an essence. Fractional distillation affords an aqueous essence flavor solution of 100—200-fold strength, which means the essence is 100 to 200 times more concentrated in flavor than the starting juice. A second method of essence recovery is to condensate the volatiles from the last effect of the evaporator they are enriched in volatile flavor components (18). 

Benzophenone. Benzophenone [119-61-9] (diphenyl ketone) exists in a stable form as colorless orthorhombic bisphenoidal prisms when crystallized from alcohol or ether. Other labile forms of lower melting point exist. Benzophenone has been identified as a flavor component of wine grapes and has a geranium-like odor. It is soluble in most organic solvents, and is insoluble in water. 

As in the United States, Canadians use com, rye, and barley malt. Their process is essentially the same as the one used by many distiHedes in the United States. Since they have no limitations on distillation proofs, distillers operate their systems for optimum separation and congener concentration. In addition, they are permitted to add blenders or flavoring components up to 9.06% by volume in the final blending after the aging process. 

Reverse Osmosis. A reverse osmosis (RO) process has been developed to remove alcohol from distilled spirits without affecting the sensory properties (14). It consists of passing barrel-strength whiskey through a permeable membrane at high pressure, causing the alcohol to permeate the membrane and concentrating the flavor components in the retentate. 

Operational temperatures of 4—27°C are maintained. In this process the flavor components are concentrated in the retentate. A reduced alcohol product is obtained by adding back water to give the desired flavor impact. Typical gas chromatographic results, comparing unprocessed 80° proof whiskey with reverse osmosis processed 54° proof whiskey and diluted 54° proof whiskey, indicate good congener retention in the alcohol-reduced (RO) processed whiskey (Table 7). 

Essential Oils. Volatile oils from plants are referred to as essential oils. The oils can be obtained through steam distillation, solvent extraction, or separation of the oils from pressed fmit. They consist of oxygenated compounds, terpenes, and sesquiterpenes. The primary flavor components of essential oils are oxygenated compounds. Terpenes contain some flavors but are often removed from the essential oil because they are easily oxidized (causiag off-flavors or odors) and are iasoluble. Essential oils are prepared from fmits, herbs, roots, and spices. 

Many instant coffee producers in the United States incorporate natural coffee aroma in coffee oil into the powder. These highly volatile and chemically unstable flavor components necessitate inert-gas packing to prevent aroma deterioration and stating from exposure to oxygen. 

Concentration. The concentration of fmit juice requites removal of solvent (water) from the natural juice. This is commonly done by evaporation, but the derived juices may lose flavor components or undergo thermal degradation during evaporation. In freeze concentration, solvent is crystallized (frozen) in a relatively pure form to leave behind a solution with a solute concentration higher than the original mixture. Significant advantages in product taste have been observed in the appHcation of this process to concentration of certain fmit juices. 

Reprinted from Journal of High Resolution Chromatography, 21, D. Juchelka et al., Multidimensional gas chromatography coupled on-line with isotype ratio mass specti ometry (MDGC-IRMS) progress in the analytical authentication of genuine flavor components , pp. 145-151, 1998, with peraiission from Wiley-VCH. 

For comparing the relative loss of a flavor component from a container, we have found the sniff test (6) very useful, especially when gas concentration measuring techniques were not available. Typical results of this type of test are shown in Table II. Each filled container was held in a glass jar for approximately 48 hours. The results are stated in qualitative, subjective terms such as slight, strong, or undetectable. The... 

Decaffeination of green coffee beans is most usually carried out with a water/solvent partition system. The green coffee beans are first steamed until they are hot, wet, and swollen, to make the caffeine available. Solvent is then used to extract the caffeine out of the aqueous phase of the beans. Finally, the beans are steamed to drive off residual solvent. The coffee beans lose their wax surface covering in the process, as well as some flavor components. For this reason, the Robusta and Brazilian Arabica coffees that are dry-processed and have the most powerful flavors are usually the types that are decaffeinated. They become milder in the process. Mechanical polishing is used to improve the appearance of decaffeinated green coffee beans if they are not to be roasted immediately. Extra care is required, however, to store these decaffeinated beans since the loss of wax covering as well as caffeine renders them much more susceptible to fungal attack. 

Radtke-Granzer, R., Piringer, O. G., Problems in the quality evaluation of roasted coffee by quantitative trace analysis of volatile flavor components, Dtsch Lebensm Rundsch, 77, 203, 1981. (CA95 95570j)... 

M. E. Miller, J. D. Stuart, Comparison of gas sampled and SPME sampled static headspace for the determination of volatile flavor components, Anal. Chem., 71, 23 27 (1999). 

Anodic hydroxylation/methoxylation of furans has an exact chemical counterpart in the well-known bromine/methanol reaction, and the choice of method is not always easily made. One can compare the two methods particularly easily in syntheses of the flavoring component, the pyrone maltol 121, from the furan 122 since one group used the electrolytic method299 and another the chemical method.300... 

As these examples indicate, the characteristic flavor of a food, fruit, etc., usually derives from a complex mixture of components. In a few cases, one unique sulfur compound is a character-impact compound, a material recognized as having the same organoleptic character as the material itself. Although some 670 compounds, of which more than 100 are sulfur-containing, have been identified in roast coffee, one material, furfurylmercaptan (2-furylmethanethiol) is considered to be a character-impact compound.43,44 The threshold level for detection of 2-furylmethanethiol in water is 0.005 ppb, and at levels of 0.01-0.5 ppb, it has the very characteristic aroma of freshly roasted coffee. However, as in many other cases, there is a concentration effect. At levels from 1-10 ppb the aroma is that of staled coffee with a sulfury note .43 Hence, 2-furylmethanethiol has a two headed property - at low concentrations it is a character impact compound and at higher levels it is an off-flavor component. 

A good example is l-p-mcnthene-8-thiol the (R) enantiomer is an important flavor component of grapefruit juice, having a very low olfactory threshold of... 

For the enantiomeric pair, (2R, 3R) 19a and (2,S , 35) 19b, the odor thresholds are very much higher (> 12 to > 30 pg L 1 in H20, not determined in air). These two materials both were contaminated with small amounts of the highly potent (2R, 35) enantiomer so these values are not too reliable. The (2R, 35) enantiomer is one of the most powerful flavor components to be discovered. 

Here x G RD and ip(x) is a spin field having N (flavor) components, ipa(x) (a = 1,2, summation over flavor and spin indices being... 

Turmeric is well established in the food supply and if it is proven to have a health effect as well as a colorant and flavor component, its future would seem assured. 

Solid phase microextraction (SPME) is an ideal approach to monitor volatile flavor components. This approach has been used to identify the volatile compounds in the headspace of fresh fruit during maturation [92], Using SPME fibers and GC/MS, the key flavor components are hexanal, 2-isobutyl-3-methoxypyrazine, 2,3-butanedione, 3-carene, trans-2-hexenal, and linalool (Fig. 8.1). In this study, the principal aroma compounds whose abundance varied during fruit development were specifically identified. 

Kubota, K. and Kobayashi, A. (1988). Identification of unknown methylketones in volatile flavor components from cooked smzWshnmp.JournalofAgriculturalandFoodChemistry 36,121-123. 

In the case of diketopiperazine 13 and related compounds, dehydrogenation of the preceding diketopiperazine occurs in the side chain. A shift of the double bond into the central ring and dehydration may result in the formation of substituted pyrazines. Simple pyrazines are known as signaling compounds from animals. The pyrazines 16 and 17 have also been isolated from marine Streptomycetes [106]. GC/MS investigations of bacterial flavor components [951 indicate that these and others are very wide-spread. 

Z0195 Miyazawa, M., and H. Kameoka. Volatile flavor components of Zingiberis rhizoma (Zingiber officinale Roscoe). Agr Biol Chem 1988 52(11) 2961-2963. 

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