Volatile flavor components

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). 

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). 

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. 

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

The importance of direct gas chromatography and combined direct GC/MS to the food industry is demonstrated by the analysis of volatile flavor components and contaminants in experimental samples of rice, food blends, and raw and roasted peanuts. By examining these samples, we are able to investigate flavor systems that are probably associated with lipid oxidation, thermal degradation of protein, or protein interactions with other compounds. 

An integrated GC/IR/MS instrument is a powerful tool for rapid identification of thermally generated aroma compounds. Fourier transform infrared spectroscopy (GC/IR) provides a complementary technique to mass spectrometry (MS) for the characterization of volatile flavor components in complex mixtures. Recent improvements in GC/IR instruments have made it possible to construct an integrated GC/IR/HS system in which the sensitivity of the two spectroscopic detectors is roughly equal. The combined system offers direct correlation of IR and MS chromatograms, functional group analysis, substantial time savings, and the potential for an expert systems approach to identification of flavor components. Performance of the technique is illustrated with applications to the analysis of volatile flavor components in charbroiled chicken. 

Flavor chemists have traditionally relied on mass spectrometry in conjunction with gas chromatography (GC/MS) to identify the structures of volatile flavor components in heated food systems. Mass spectrometry provides the molecular weights of fragment ions, which are useful for deducing-molecular structure. The MS detection limit is on the order of 1CT g, however detection limits for target compound analysis or chemical class detection via selected ion monitoring can be much lower. Extensive libraries of mass spectra are available even so, many new flavor compounds can often not be identified from MS data alone. 

Volatile Flavor Components in Thermally Processed Louisiana Red Swamp Crayfish and... 

As shewn in Table I, many volatile flavor components were identified in the samples analyzed. Lipid composition generally affects storage stability of various foods. Cmega-3 polyunsaturated fatty acids (PUFA) have been identified in the edible portions of pond-raised and wild crayfish. Crayfish were reported to have higher levels of cmega-3 PUFA than... 

There are tvo approaches to meat flavor analysis one is concerned vith the isolation and identification of volatile flavor components, and the other involves identification of non volatile flavor precursors. 

Hundreds of compounds have been identified in the volatile flavor components of processed foods. Hydrocarbons, alcohols, ethers, aldehydes, ketones, acids, acid anhydrides, esters, aromatic, lactones, pyrones, furans, pyridines, pyrroles, n-alkylpyrrole-2-aldehydes, pyrazines, sulfides, disulfides, thiols, thiophenes, thiazoles, trithiolanes, thialdine. ..etc. 

Pyridine and its derivatives. The most unique pyridine derivative isolated from processed food is l,lt,5,6-tetrahydro-2-ace-topyridine. This compound was prepared by roasting proline and dihydroxyacetone at 92°C in presence of sodium bisulfate, and exhibited a strong odor reminiscent of freshly backed soda crackers (82). 2-Ethylpyridine and 2-pentylpyridine were reported in volatile flavor components of shallow fried (83). Pyridine, 2-methylpyridine, 3-methylpyridine, 2-ethylpyridine, 3-ethylpyri-dine, 5-ethyl-2-methylpyridine, 2-butylpyridine, 2-acetylpyridine, 2-pentylpyridine, 2-hexylpyridine, 3-pentylpyridine, 5-methyl-2-pentylpyridine, and 5-ethyl-2-pentylpyridine were identified in the volatiles of roasted lamb fat (8H). 2,5-Dimethylpyridine and... 

The flavor impression of a food is influenced by compounds that affect both taste and odor. The analysis and identification of many volatile flavor compounds in a large variety of food products have been assisted by the development of powerful analytical techniques. Gas-liquid chromatography was widely used in the early 1950s when commercial instruments became available. Introduction of the flame ionization detector increased sensitivity by a factor of 100 and, together with mass spectrometers, gave a method for rapid identification of many components in complex mixtures. These methods have been described by Teranishi et al. (1971). As a result, a great deal of information on volatile flavor components has been obtained in recent years for a variety of food products. The combination of gas chromatography and mass spectrometry can provide identification and quantitation of flavor compounds. However, when the flavor consists of many compounds, sometimes several hun-... 

In another thorough flavor study Wu et al.(55) determined both the volatile and nonvolatile flavor compounds found in mushroom blanching water. They used HPLC to determine such non volatile flavor components as sugars, amino acids and nucleotides. The free amino acids were analyzed to determine if they might be involved in any thermal reactions which might produce Amadori compounds or Strecker aldehydes which in turn would produce aroma components. 

The spectrvun of volatile flavor components of cooked meats from different species was Investigated. 

All possible combinations of methyl, propyl, allyl, and 1-propenyl disulfides (primarily), monosulfides, and trisulfides have been found among the volatile flavor components of onion (28,29, 30,31), garlic (32), caucas Allium victorialis) (33), and other Allium species 28) although proportions vary with species. These compounds are presumably derived from the corresponding thiolsulfinates. This is accomplished either by direct decomposition by an unknown mechanism with evolution of SO2 (32) or by interaction with cysteine to produce a mixed disulfide (15),... 

The process for cholesterol removal from anhydrous milkfat was patented by General Mills (41). Fractionment Tirtiaux also disclosed the development of a vacuum steam distillation system called the LAN cylinder (38). The steam distillation process (Figure 2) was commercialized, producing a 90-95% cholesterol reduction in anhydrous milkfat with a 95% yield that was reconstituted into 2% fat fluid milk (42). The major disadvantage to the process is that it strips or removes most all volatile flavor components from the fat. These flavor components must be captured (i.e., vacreation) before the distillation process to attempt to reproduce the delicate flavors so desired for reconstitution into a butter product. 

The volatile flavor components, which are normally stripped from the food during conventional frying, are retained in the confines of the fryer. 

A Romano cheese-like aroma was produced from a butter-fat emulsion by treating it with a crude enzyme mixture isolated from Candida rugosa. The emulsion consisted of 20% butterfat and 1.5% Tween 80 in a buffer solution. The treated emulsion was held at 37°C for three hours and then aged at room temperature for three days to develop the cheese-like flavor. The volatile flavor components were isolated from both the enzyme modified butterfat (EMB) and a commercial sample of Romano cheese. The flavor isolates were separated into acidic and nonacidic fractions and analyzed by gas chromatography-mass spectrometry. The results showed good correlation between the acidic fractions of the two samples. The acidic fractions contained similar relative concentrations of eight short-chain fatty acids (C2 - Cj q). Methyl ketones and esters were major components in the nonacidic fraction of the EMB. 

In one example the ground material was extracted with CO2 at 160 atm and 25 C a 98.5% yield of aromatics was obtained. The CO2 extract and an alcohol exffact of another sample of ground vanilla beans were used in comparative tests to flavor ice cream mixtures. In an evaluation test by a panel of 14 persons, the ice cream flavored with CO2 extract was preferred unanimously. Gas chromatographic analyses of the CO2 and alcohol extracted materials showed that the CO2 extract contained 20 to 30% more of the components responsible for vanilla flavor, and additionally, the CO2 extract was found to contain some high volatile flavor components which were not detected in the alcohol extract. 

Gow, C.Y. and Hsin, T.L. 1999. Changes in volatile flavor components of guava juice with high-pressure treatment and heat processing and during storage. Journal of Agricultural and Food Chemistry 47 2082-2087. 

Nunomura N., Sasaki M., Asao Y. and Yokotsuka T. (1978) Shoyu (soy sauce) volatile flavor components basic fraction. Agric. Biol. Chem. 42, 2123-8. 

There are hmited adsorbents. A widely used one is poly(dimethylsiloxane), which is useful for screening for volatile flavor components of beverages, foods. 

Deodorization. Volatile flavor components of soybean have been investigated in detail (79, 80, 81, 82). Arai et al. (83) have studied the interaction of denatured soybean protein with 1-hexanol and 1-hexanal which are the typical beany flavor compounds of raw and processed soybeans. These protein-bound compounds are liberated by treating the denatured soybean protein with pepsin (83). Noguchi et al. (84) observed that not only 1-hexanol and 1-hexanal but also other flavor compounds are effectively liberated and removed from a soybean protein isolate during treatment with an acid protease (Molsin). A subsequent study has ascribed this effect to the activity of aspergillopeptidase A, an endopeptidase, which has been identified as a main constituent of Molsin (85). Fujimaki et al. (88, 87) examined several protease preparations for their usefulness in deodorization and reported that a pepsin treatment followed by ether extraction is most effective for deodorizing some protein preparations of soybean and fish. 

These results were interpreted as an indication that the relatively high molecular weight, nonvolatile tobacco wax components were the major precursors in tobacco of the PAHs in smoke, whereas the moderate to low molecular weight and volatile flavorful components in tobacco did not contribute significantly to the PAH levels in smoke. 

Torres, M.M., Martinez, M.L., and Maestri, D.M., A multivariate smdy of the relationship between fatty acids and volatile flavor components in olive and walnut oils, J. Am. Oil Chem. Soc., 82, 105-110, 2005. 

Soon after harvest, tree nuts, because of their high concentrations of unsaturated fatty acids, may undergo development of oxidative rancidity. This leads to the formation of undesirable rancid flavors and a decline in both unsaturated fatty acids (e.g., oleic, linoleic, and linolenic acids) and natural antioxidants (e.g., tocopherols) [63]. The postharvest stability and sensory quality of tree nuts are influenced by several factors such as chemical composition (e.g., fatty acid composition and presence of antioxidants such as tocopherols), moisture content, oxygen concentration, and temperature, among others. There is some evidence that lipid oxidation is at least in part due to the action of oxidative enzymes, such as lipoxygenases. This is supported by the fact that mild to moderate heat treatment of some nuts, such as pecan, retards the development of rancid flavors during storage [64,65]. Nevertheless, mild oxidation is probably necessary for the development of the characteristic volatile flavor components of natural tree nuts [63], In addition to the Upid oxidation volatiles, some other compounds, such as terpenes, lactones, and short-chain volatile acids, may impact the aroma profiles of some types of natural flee nuts. 

Chandrasekaran SK, King CJ. Retention of volatile flavor components during drying of fruit juices. Chem Eng Prog Symp Ser 67(108) 122-130, 1971. 

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