Compounds affecting flavor

The common practice of adding iron to breakfast cereals or to vitamin supplements exemplifies the first. Here the first requirements are cosmetic, that the iron-containing compound added should not cause discoloration or adversely affect flavor. It is also an advantage for the added iron-containing compound to be sparingly water-soluble, but for the iron to be reasonably bioavailable and not be incompatible with other constituents (335). There is a great deal of inorganic and physical chemistry involved in these matters, most of which is buried in the technical and patent literature. 

Food flavor is governed by many factors, including lipid oxidation and protein degradation. Enzyme-catalyzed oxidation ( ) and autoxidation (2) can substantially alter the flavor q ality of foods. In "addition, protein degradation, whether caused by enzymes, heat, or interactions with other compounds, can also affect flavor characteristics of certain foods (3, 4, ... 

Dupuy and coworkers have reported a direct gas chromatographic procedure for the examination of volatiles in vegetable oils (11). peanuts and peanut butters (12, 13), and rice and com products (14). When the procedure was appTTed to the analysis of flavor-scored samples, the instrumental data correlated well with sensory data (15, 16, 17), showing that food flavor can be measured by instrvmental means. Our present report provides additional evidence that the direct gas chromatographic method, when coupled with mass spectrometry for the identification of the compounds, can supply valid information about the flavor quality of certain food products. Such information can then be used to understand the mechanisms that affect flavor quality. Experimental Procedures... 

Lawrence, W. C., Volatile Compounds Affecting Beer Flavor, Wallerstein... 

Fat portion of meats, particularly their phospholipid components, undergo autoxidation/degradation (2) and produce an overwhelming number of volatiles. Fats also serve as a depot of fat-soluble compounds that volatilize on heating and strongly affect flavor. Since compositional characteristics of lipids in meats, vary from one species to another, these factors may be responsible for the development of some species-specific flavor notes in cooked meats (8.9 ). Obviously presence of 4-methyloctanoic and 4-... 

DHA can be reduced to RAA by chemical agents, such as hydrogen sulfide or enzymatically, by dehydroascorbic acid reductase. The conversion of DHA to diketogulonic acid (DKG) is irreversible and occurs both aerobically and anaerobically, particularly during heating. This reaction results in loss of biological activity. The total oxidation of RAA may result in the formation of furfural by decarboxylation and dehydration. With subsequent polymerization, the formation of dark-colored pigments results. These compounds affect the color and flavor of certain foods, such as citrus juices, and decrease nutritive value. 

In dairy products the lipid component is an important contributor of dairy flavor. Compounds such as mono- and di-carbonyls and volatile fatty acids impart flavor to milk though present only in low concentrations. Saturated and unsaturated aldehydes and various ketones affect flavor though present in concentrations of ppm or ppb (15). 

The sensory effects of volatile compounds depend on the chain length, type of functional group, and positional and geometric isomerism. The same aldehyde can produce different odors and flavors in aqueous and oil solutions, the threshold being much lower in the former medium. In oil-in-water emulsions such as mayonnaise, the oil-water partition coefficient (Pq/ ) of a given compound affects its sensory impact on the emulsion (Jacobsen, 1999). 

The objective of this study, therefore, is to assess which compound, which affects customer contentment for RTD tea flavor notes, would be successful in the market. In order to identify the hidden pattern of the customer s needs, the artificial neural networks (ANNs) have been applied to classify the key volatile compound of the flavors. In this study, the RTD tea segment is selected as a case study due to market trend. The 4 customer groups and 5 compounds of flavor are used as a data. 

When one considers the effects of chemical interactions (carbohydrate aroma) on sensory perception, one would expect that aroma character and/or intensity will be altered. This is because the various polysaccharides will interact with different aroma compounds to varying degrees, i.e., change the balance of aroma compounds liberated from a food. However, the effect of carbohydrates on limiting mass transfer would be expected to likely affect flavor intensity and not character. This is because mass transfer effects would be more uniform across aroma compounds. 

Humidity does not affect the permeabihty, diffusion coefficient, or solubihty coefficient of flavor/aroma compounds in vinyhdene chloride copolymer films. Studies based on /n j -2-hexenal and D-limonene from 0 to 100% rh showed no difference in these transport properties (97,98). The permeabihties and diffusion coefficients of /n j -2-hexenal in two barrier polymers are compared in Table 12. Humidity does not affect the vinyhdene chloride copolymer. In contrast, transport in an EVOH film is strongly plasticized by humidity. 

Other phenolic compounds of commercial importance include the terpenoids, including mono, di, tri, and sesquiterpenes. While most of these are used as essential oils, fragrances, and flavors in various products, they are toxins in certain species. For example the sesquiterpene lactones of the Centaurea species cause an irreversible Parkinson s-like condition in horses called nigro-pallidal encephalomalacia. This is a lethal condition and the prognosis for recovery is grave in most cases, affected horses should be euthanized before reaching the terminal stages. 

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