Flavor constituents

Congeners. Congeners are the flavor constituents in beverage spirits that are responsible for its flavor and aroma and that result from the fermentation, distillation, and maturation processes. 

Second, the essential amino acids leucine, isoleucine, and phenylalanine are precursors for several additional tomato flavor elements. Here, too, these flavor elements are important flavor constituents in other fruits, including strawberries and apples. They are also found in breads, cheeses, wine, and beer. 

Cholesterol can be extracted more effectively from beef tallow with the addition of adsorbents such as activated alumina, silica gel or molecular sieve to the extraction chamber, but flavor constituents are removed as well. 

Recent developments In microcomputers, sensory analysis and experimental design have made it possible to efficiently evaluate and optimize products. This paper focuses on the conduct and analysis of a study to optimize the flavor constituents of an alcoholic "digestive" liqueur. It illustrates the use of the panel data, and the contributions of the microcomputer as both a tool for gathering data, and as an inexpensive replacement for mainframe computers in statistical computations. 

The industrial flavor producers offer a very broad selection of natural and synthetic flavors,mainly in the form of liquid concentrates.The majority of flavor constituents in such concentrates exhibit considerable sensitivity to air,light irradiation and elevated temperature. These flavor concentrates are moreover oily,greasy rather lipophilic materials,which are difficult to work with. The natural plant extracts also have microbiological contaminations that need to be removed. 

Among the most recent and sophisticated flavor encapsulation processes,cyclodextrin complexation represents a special way of encapsulation entrapment of flavors on the lowest possible scale,which is called molecular encapsulation.In this process,every flavor constituent is surrounded by a cyclodextrin ring which offers an almost perfect protection against damaging effects of the environment.The most significant advantages of the application of molecular encapsulation in the food industry and cosmetics are as follows/1/ ... 

Experiments were also carried out at 80 and lOO C. According to our observations at these high temperatures, solid- phase chemical transformations may take place between certain flavor constituents and cyclodextrin hydroxyls/monoterpene alcohols and phenolic compounds appear as a result of a solid-phase transacetylation of terpeneaoetates and phenyl-acetates with the simultaneous formation of cyclodextrin-acetates/. Long term heat treatments of cyclpdextrin-flavor complexes should not be run above 6o°C in order to avoid such phenomena. 

The molecular encapsulation of flavors with cyclo-dextrins was found to improve the resistence of light sensitive flavor constituents against daylight and ultraviolet irradiation. The photodecomposition of adsorbed and complexed flavors was tested both in the solid state and in aqueous solutions. The results of the light stability tests are demonstrated in the example of complexed and adsorbed citral,beta-ionone and cinnamaldehyde formulations /Table III./. 

This phenomenon might be due to the partial release of the entrapped flavor constituents upon the dissociation of the inclusion complexes in aqueous systems. 

The research enologist requires many different procedures depending on the requirements of the experiment. Research on flavor constituents requires the most sophisticated techniques of modem organic chemistry. 

Quality standards for some flavor constituents will eventually be developed—linalool for muscats, for example, and perhaps phenethanol for certain types of wine. Kahn and Conner (124) have published a rapid GLC method for phenethanol. It has been suggested (60) that detection of bacterial activity from the presence and amount of minor bacterial byproducts (arabitol, erythritol, and mannitol) may be useful. Based on GLC determination of carbonyls, esters, and higher alcohols, beers were accurately classified into three categories (125). Anthocyanin content has been determined quantitatively by using molar absorbance values for five anthocyanin pigments (126). 

Vacuum distillation is preferred by many flavoring producers because it is more rapid than steam distillation. In this method, Ihe drying and resinification of flavoring constituents is avoided because of the absence of air. The separation of closer-boiling-point materials is more effective under vacuum. Undesirable side reactions between constituents are avoided because of the relatively low temperatures required. Thus, many delicate substances can be handled without thermal degradation. 

Moshonas, M. G. Analysis of carbonyl flavor constituents from grapefruit oil. J. Agric. Food Chem., 1971, 1 , 769-770. 

Excessive pressure used in hand-reaming of citrus fruit can also result in juice containing high peel oil content and perhaps significant amounts of undesirable flavor constituents (primarily of a bitter nature) as well. Since high peel oil and undesirable flavor constituents would seriously affect sensory evaluation results in a negative way, care should be taken in hand-reaming citrus fruit to apply only as much pressure as necessary to extract most but not all of the juice. In this way the amounts of peel oil and undesirable flavor factors will be held to normal levels. 

The flavor constituents of plain and roasted cashew nuts have not been previously reported in the literature. In the present study, aroma compounds have been isolated from plain, oven-roasted and oil-roasted cashew nuts by simultaneous distillation extraction and by steam distillation followed by selective extraction, after pH adjustment. Compound identification was carried out by GC and GC-MS analyses. Esters and lactones are present in plain cashews whereas roasted samples also contain pyrazines. 

Cashew kernels possess pleasant taste and flavor and are eaten either raw or roasted with salt. The raw nuts, which are packed in flexible packages, are usually marketed as plain cashews. The roasted nuts are usually fried in vegetable oil to light brown colour, salted and packed in cans. The flavor characteristics of plain cashew nuts are enhanced as a result of oil roasting. A literature review revealed that the flavor constituents of plain or roasted cashew nuts have not been investigated previously. In the present study, the authors have attempted to isolate the flavor compounds by steam distillation and extraction and to identify them by GC and GC-MS techniques. Thirty six compounds have been identified for the first time. 

JAYALEKSHMY AND NARAYANAN Flavor Constituents of Cashew Nuts 357... 

Preliminary GC analysis revealed that there are more number of peaks in roasted samples compared to plain cashews. Also selective extraction method was found to be slightly superior to the SDE method under the conditions of the experiment adopted in this study. However, the compounds in oven-roasted and oil-roasted samples did not differ much, qualitatively and quantitatively. In total, 26 compounds have been identified in plain cashews and 3 compounds in roasted samples. The identified peaks constituted 70 percent of the total peaks registered in GC analysis of the individual samples. The descriptive flavor profile of the eluting peaks of the plain and roasted samples were studied. Since the flavor isolate from oven roasted cashew nuts contained the flavor components of plain cashews also and since analysis showed that there was not much difference between the flavor constituents of oven-roasted and oil-roasted samples, the aromagram of the oven-roasted cashew nuts (SDE) was taken as representative. Fig.l gives the GC profile of oven roasted cashew nuts and the sensory properties of the numbered peaks are included in Table III. 

To sum up, the flavor constituents of plain and roasted cashew nuts are reported here for the first time. The mild flavor of cashew nuts can be attributed to the carbonyls, esters and lactones, especially to 5-heptene-2-one and 1,3-propanediol diacetate. Upon roasting, 2,6-dimethyl pyrazine, 2,6-diethyl pyrazine and the furanone are formed in larger amounts and from flavor profile also these compounds are likely to play a significant role in the characteristic aroma of roasted cashew nuts. 

The chemical class of the thiaalkanethiols has been reported by different authors as flavor constituents (17,18,28-30). According to the patent literature, 1-methylthioethanethiol 1 7 is extremely useful for meat flavors (3 1, 3 ). A one-step synthesis of dithiohemiace-tals was published by L. Schutte in 1971 (3 3. ... 

The purpose of this book is to review aromas that are developed by thermal processes. Because the flavor of heated foods is affected principally by aroma, we focus attention exclusively on the volatile flavor constituents of foods. Moreover, we intend this book to complement the 1986 book. Biogeneration of Aromas, ACS Symposium Series 317, edited by Thomas H. Parliment and Rodney Croteau. A broader overview of the Maillard reaction was discussed in the 1983 book, The Maillard Reaction in Foods and Nutrition, ACS Symposium Series 215, edited by George R. Waller and Milton S. Feather, which addressed the volatile, nonvolatile, and nutritional aspects of the Maillard reaction. 

Moshonas, M. G. and Shaw, P. E. (1989). Flavor evaluation and volatile flavor constituents of stored aseptically packaged orange juice. ]. Food Sci. 54, 82-85. 

More details of the plastein reaction and its application to remove pigments such as chlorophyll, or to remove off-flavor components such as the beany taste of soybeans, are shown in Figure 2. The protein of the food system is solubilized and denatured (in order to achieve proteolysis), a protease is added, and the hydrolytic reaction is allowed to proceed. On partial hydrolysis of the protein the pigments and flavor constituents are released from the protein they are removed, the hydrolyzate is concentrated, and resynthesis and/or rearrangement of the amino acid sequence of the polypeptides is catalyzed by the same or a different protease. Resynthesis also can be carried out in the presence of added amino acid esters in order to improve the nutritional/functional properties of the protein. 

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