Flavor compounding

Flavor characterization Flavor compounding Flavor enhancer Flavor-filled capsules Flavoring agent Flavoring agents... 

Chemical compounds having odor and taste number in the thousands. In 1969 a description of the odor characteristics of more than three thousand chemical compounds used in the flavor and perfume industries were described (41). The Hst of volatile compounds found in food that may contribute to odor and taste is even larger (42), and the Hst of all possible flavor compounds, including those that have yet to be synthesized, is greater than a thousand. Many different compounds have the same flavor character or quaUty, differing perhaps in their relative intensity but indistinguishable in the type of flavor they ehcit. The exact number of different flavor quaUties is not known, but it appears to be much less than the total number of compounds with flavor. 

Flavor Portion. A flavor compound consists of a flavor portion, ie, flavor character impact item(s), as well as flavor contributory and flavor differential items, and a diluent portion. 

The flavor portion of a flavor compound gives it its name, acceptabiUty, and palatabiUty, and provides character fixation of the flavor, ie, relatively high boiling point soflds, usually in combination, are used at concentrations above thek threshold values at use level so that upon dilution the levels remain above threshold value and the perception of the flavor does not change. 

Diluent Portion. The diluent portion of a flavor compound is the carrier for the color and the flavor, ie, the solvent for the flavor portion. It keeps the flavor homogenous, ie, keeps soflds in solution retards chemical reactions from occurring and regulates flavor strength, ie, the greater the amount of solvent, the weaker the flavor. 

Compounded Flavors. Liquid or dry blends of natural or synthetic flavor compounds are called compounded flavors. Most commercial preparations are available as water- and oil-soluble Hquids, spray-dried and plated powders, emulsions, and carbohydrate-, protein-, and fat-based pastes. Compounded flavors are used throughout the food industry in confections, baked goods, snack foods, carbonated beverages, and processed foods (53). 

The rate of aspartame degradation in dry mixes is more dependent on the water activity than on the temperature (23). In dry mixes, aspartame may also engage ia Maillard reactions with the aldehyde moieties of flavoting agents, resulting ia the loss of sweetness and flavor. Use of the corresponding acetals of the flavor compounds to avoid this reaction has been reported (24). 

Although flavor precursors in the unroasted cocoa bean have no significant chocolate flavor themselves, they react to form highly flavored compounds. These flavor precursors include various chemical compounds such as proteins, amino acids, reducing sugars, tannins, organic acids, and many unidentified compounds. 

The natural moisture of the cocoa bean combined with the heat of roasting cause many chemical reactions other than flavor changes. Some of these reactions remove unpleasant volatile acids and astringent compounds, partially break down sugars, modify tannins and other nonvolatile compounds with a reduction in bitterness, and convert proteins to amino acids that react with sugars to form flavor compounds, particularly pyrazines (4). To date, over 300 different compounds, many of them formed during roasting, have been identified in the chocolate flavor (5). 

Coffee bioconversions through enzymatic hydrolysis have been used to modify green coffee and improve the finished product (60). Similarly, enzymes have been reported which increase yield and improve flavor of instant coffee (61). Fermentation of green coffee extracts to produce diacetyl [431 -03-8] a coffee flavor compound, has also been demonstrated (62). 

Malted barley contains a- and P-amylases along with proteases and phytases. Most standardi2ed microbial en2yme preparations for industrial starch conversion contain approximately 100 times more amylase activity than malt. In beermaking, malt is not just valuable for its en2ymes but also for flavor compounds. 

Perfumes, Flavors, Cosmetics, and Soap. Many naturally occurring esters in essential oils and some synthetic esters are important fragrance and flavor compounds (61,62). They are used in perfumes, flavors, cosmetics, soaps, detergents, and air fresheners. Benzyl, butyl, ethyl, methyl, and phenyl esters of benzoic acid are used as flavors, perfumes, and food preservatives. Glyceryl 4-aminobenzoate [136-44-7] and 2-ethyUiexyl 4-dimethylaminobenzoate [21245-02-3] are used in cosmetic sunscreen preparations. Alkyl esters of 4-hydroxybenzoic acid, called parabens, have been used under various names for fungus infections of the skin, and as preservatives in lotions and creams (101). Soap and cosmetic fragrances use large amounts of amyl and benzyl saHcylate. Benzyl saHcylate [118-58-1] is also used in deodorant sprays. 2-Ethylhexyl saHcylate [118-60-5] and 2-ethylhexyl 4-methoxycinnamate [5466-77-3] are used in sunscreen formulations (102). 

A. Mosandl, K. Eischer, U. Hener, P. Kieis, K. Rettinger, V. Schubert and H.-G. SchmaiT, Stereoisomeiic flavor compounds. 48. Cliirospecific analysis of natural flavor s and essential oils using multidimensional gas cliromatography , ]. Agric. Food Chem. 39 1131-1134(1991). 

Figure 10.1 Analysis of racemic 2,5-dimethyl-4-hydroxy-3[2H]-furanone (1) obtained from a strawbeny tea, flavoured with the synthetic racemate of 1 (natural component), using an MDGC procedure (a) dichloromethane extract of the flavoured strawbeny tea, analysed on a Carbowax 20M pre-column (60 m, 0.32 mm i.d., 0.25 p.m film thickness earner gas H2, 1.95 bar 170 °C isothermal) (b) chirospecific analysis of (1) from the sti awbeny tea exti act, ti ansfened foi stereoanalysis by using a pemiethylated /3-cyclodextrin column (47 m X 0.23 mm i.d. canier gas H2, 1.70 bar 110 °C isothemial). Reprinted from Journal of High Resolution Chromatography, 13, A. Mosandl et al., Stereoisomeric flavor compounds. XLIV enantioselective analysis of some important flavor molecules , pp. 660-662, 1990, with permission from Wiley-VCH.

A. Mosandl, U. Hener, U. Hagenauer-Hener and A. Kuster mann, Stereoisomeric flavor compounds. 33. Multidimensional gas chromatography dkect enantiomer separation of -y-lactones from fr uits, foods and beverages , 7. Agric. Food Chem. 38 767-771 (1990). 

B. Weber, B. Maas and A. Mosandl, Stereoisomeric flavor compounds. 72. Stereoisomeric distribution of some cliiral sulfur containing trace components of yellow passion fruits , ]. Agric. Food Chem. 43 2438-2441 (1995). 

A. Mosandl, G. Bmche, C. Askaii and H.-G. SclimaiT, Stereoisomeric flavor compounds. XLIV enantioselective analysis of some important flavor molecules , ]. High Resolut. Chromatogr. 13 660-662 (1990). 

M. T. Belay and C. E. Poole, Determination of vanillin and related flavor compounds in natural vanilla exti acts and vanilla-flavored foods by thin layer chromatography and automated multiple development , Chromatographia 37 365-373(1993). 

Benzaldehyde has limited uses as a chemical intermediate. It is used as a solvent for oils, resins, cellulose esters, and ethers. It is also used in flavoring compounds and in synthetic perfumes. 

Scheme 9.34 Synthesis of a flavor compound by genetically evolved dioxygenases.

OHARA A, FAN Y J and MATSUHISA T (2001) Flavor compounds responsible for antimutagenicity of tea infusion , in Proc of Intern Symp on Tea Sci, 6-8 October, 2001, Shizuoka, Japan, 214-17. 

Food and natural products represent the next largest body of work in SFE. Major topics include the isolation and characterization of high value-added fragrances and flavor compounds from novel natural materials and agricultural by-products. SFE is increasingly applied to extract oils, flavors, colorants, resins, etc., avoiding the use of hexane and petroleum fractions. 

In outline, a percolation process is used to produce an aqueous coffee extract, which in turn is dehydrated to yield water-soluble solids. Instant and soluble coffees are synonymous for these water-soluble coffee extract solids. Usually some of the volatile aroma and flavor compounds, which are lost during the processing, are added back immediately before packaging. 

Methods of fixing the volatile aroma and flavor compounds separately from the instant coffee powder have been developed. The volatile mixture can be mixed with aqueous gelatin or gum arabic and spray dried. The oily droplets of the flavor and aroma compounds are coated with gelatin or gum arabic in a dry lattice. This powder can be mixed in with instant coffee powder and is relatively stable in the presence of air. Emulsification with sugar is also a highly effective way of trapping and preserving coffee volatiles, but is of limited use for instant coffees. 

Marasco, E. and C. Schmidt-Dannert (2003). Towards the biotechnological production of aroma and flavor compounds in engineered microorganisms. Appl. Biotechnol. Food Sci. Pol. 1(3) 145-157. 

Zorn, H., S. Langhoff et al. (2003a). Cleavage of beta,beta-carotene to flavor compounds by fungi. Appl. Microbiol. Biotechnol. 62(4) 331-336. 

Sulfur compounds are renowned for unpleasant odors beginning with the rotten egg smell of H2S and many are responsible for the off-flavors of various foods. Nevertheless, some sulfur compounds provide the pleasant odors associated with many plants and are also prominent in desirable food flavors. The determination of flavor or aroma is very complex since large numbers of components may be involved both for microorganisms and plants. Many flavor compounds, of course, do not contain sulfur. Much has been and continues to be written. We can only convey an eclectic flavor of the many situations involving sulfur compounds - a tasting menu. The colorful language of experts in aroma and taste bears a close resemblance to that of enophiles. 

Mushrooms have been investigated with especial reference to shiitake, Lentinus edodes, the flavorful fungus widely used in Chinese and Japanese dishes. While the umami taste is attributed to guanylic acid, lentinic acid 14 (Scheme 6) is converted to lenthionine, 1,2,3,5,6-pentathiacycloheptane 15, a compound with the characteristic shiitake flavor. This complex reaction requires a C-S lyase enzyme.30 Other important flavor compounds are 1,2,4,6-tetrathiacycloheptane 16 (Scheme 6) and 1,2,3,4,5,6-hexathiacycloheptane (not shown). 

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