Predominant volatile components

Another investigation reported the esters as the predominant volatile components of the Maradol variety (about 41% w/w of the total volatiles) [51]. The major representative compounds in the simultaneous steam distillation-solvent extraction were methyl butanoate and ethyl butanoate. Previous work described the esters as the predominant compounds among the volatiles papayas, for example, from Sri Lanka and Colombia had 52 and 63% of esters in the total volatiles respectively [25,41]. 

The chemical nature of flavor volatiles was representative of most classes of organic compounds. Hexanal was found to be the predominant volatile component In each case and Its content was directly proportional to the amount of TBA-reactlve species, while Inversely proportional to the flavor acceptability of meats. Nitrite curing depressed the production of lipid oxidation products and nltrlte-free curing composition duplicated the action of nitrite on meat, flavorwlse. 

The reactive role of liptinite macerals in liquefaction has been partially documented (50,68). However, recent work has shown that unaltered sporinite often is encountered in the residues from both batch and continuous liquefaction runs. For example, sporinite was a common component in the residues of a high volatile A bituminous coal after hydrogen-transfer runs at 400° for 30 minutes (70). In spite of the relative unreactivity of the sporinite in this instance, the vitrinite clearly had reacted extensively because vitroplast was the predominant residue component. The dissolution rate of sporinite from some coals, even at 400°C, may be somewhat less than that of vitrinite. 

Figure 4.1 depicts the difference between these two modes. Since there is no longer any partitioning of the analyte between the condensed phase and the vapour phase, compounds of limited volatility may yield a higher vapour pressure in this mode than by the conventional headspace approach, where they predominantly remain in solution. InvolatUe materials (such as API usually) do not vaporise, but instead condense onto the inside of the vial. The headspace vial effectively becomes a disposable injector liner. Care must be taken to operate at an incubation temperature that will not cause degradation of API into volatile components, which might interfere with the analysis. 

Later, the chemical characterisation of the volatiles from yellow passion fruit essence and from the juice of the fruit was done by GC-MS and GC-olfactom-etry (GC-O) [27]. Esters were the components found in the largest concentrations in passion fruit juice and essence extracted with methylene chloride. Analysis by GC-O yielded a total of 66 components which appeared to contribute to the aroma of passion fruit juice and its aqueous essence. Forty-eight compounds were identified in the pulp of Brazilian yellow passion fruits (Passiflora edulis f. flavicarpa) [48]. The predominant volatile compounds belonged to the classes of esters (59%), aldehydes (15%), ketones (11%), and alcohols (6%). 

The present study deals with the identification of predominant aromti-active compounds in saffron by AbDA. In order to assure that the results of AED. were representative of saflVon aroma, volatile components were isolated by two e iractiuti techniques. 

This review demonstrates that over the past four decades, considerable effort has gone into the determination of the volatile compounds in natural and roasted tree nuts. It is also evident that lipid oxidation plays a predominant role in the generation of the characteristic volatile components of aU types of natural tree nuts. Unfortunately, there is insufficient information available to clearly define the key aroma components of most of the natural tree nuts reviewed in this chapter. In general,... 

Composition Genuine essential oils consist exclusively of volatile components with boiling points mainly between 150 and 300 °C. They contain predominantly hydrocarbons or monofunctional compounds such as aldehydes, alcohols, esters, ethers, and ketones. Parent compounds are mono- and sesquiterpenes, phenylpropane derivatives, and longer-chain aliphatic compounds. Accordingly, essential oils are relative non-polar mixtures, i.e., they are soluble in most organic solvents. Often the organoleptic properties are not determined by the main components but by minor and trace compounds such as, e.g., 1,3,5-undecatrienes and pyrazines in galbanum oil. In many of the commercially important oils, the number of identified components exceeds 100. Very many of the constituents are chiral, frequently one isomer predominates or is exclusively present, e. g., (- )-menthol in peppermint oils or (-)-linalyl acetate in lavender oil. 

All the reported sulfur-containing volatile components of YAs and YEs are summarized in Table I. Numerically, different classes of sulfur compounds predominate in the various investigations. None of the compounds reported in YEs has been mentioned in more than two studies, and most have been reported in only one study. This may be due to the investigation of YEs processed under different conditions and/or to different analytical conditions used for the volatiles analysis. 

Predominant fluid flow pattern A material balance on the volatile component can be written as ... 

In a preliminary study, the volatile fraction of cork samples at different stages of processing (raw material and finished stoppers) was analyzed [43]. One hundred seven components were identified by GC-MS, several of which had not been previously reported in cork. Predominant volatiles were hydrocarbons, alcohols, acids, and carbonyl compounds. A natural origin, such as chemical or enzymatic degradation of the cork, could explain the occurrence of many substances. All the identified compounds with a phenyl ring and with a linear structure, e.g., vinylbenzene, benzyl alcohol, and 2-hydroxybenzaldehyde, could be derived from suberin and lignin. 

OC. These active compounds are endocrine products of glands found in tire plant placenta and are a mixture of two unsaturated and three saturated homologs (Figure 11.10). Capsaicinoids are isolated through a volatile solvent extraction of the dried, ripened fruit of chili peppers. The capsaicinoids are distilled, dried, and compoimded togetiier. The final oleoresin contains several branched-chain alkyl vanillylamides, in addition to capsaicin, the major component in OC. The predominant capsaicinoid components of OC are capsaicin (70%), dihydrocapsaicin (20%), norhydrocapsaicin (7%), homocapsaicin (1%), and homodihydrocapsaicin (1%) (Salem et al., 2006) (Figure 11.10). 

The reactor effluent is thus likely to contain hydrogen, methane, benzene, toluene, and diphenyl. Because of the large differences in volatility of these components, it seems likely that partial condensation will allow the effluent to be split into a vapor stream containing predominantly hydrogen and methane and a liquid stream containing predominantly benzene, toluene, and diphenyl. 

Precipitation of the active component precursor starts when its concentration in the liquid phase reaches the saturation point Cs. At this point the degree of pore volume filling is Us. If the precursor is not volatile, one can determine Us as a ratio of Us=U0C0/CS. The redistribution of the precursor is minimal if Us< t/cr h. Aspiration of Us to U0 results in a predominant yield of the precursor at the external surface of a support grain. 

The amount of ethylene is limited because it is necessary to restrict the amount of unsaturated components so as to avoid the formation of deposits caused by the polymerization of the olefin(s). In addition, ethylene [boiling point —104°C (—155°F)] is more volatile than ethane [boiling point —88°C (—127°F)], and therefore a product with a substantial proportion of ethylene will have a higher vapor pressure and volatility than one that is predominantly ethane. Butadiene is also undesirable because it may also produce polymeric products that form deposits and cause blockage of lines. 

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