Vanilla, flavor compounds

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). 

Many aldehydes are particularly fragrant. A number of flowers, for example, owe their pleasant odor to the presence of simple aldehydes. The smells of lemons, cinnamon, and almonds are due to the aldehydes citral, cinnamalde-hyde, and benzaldehyde, respectively. The structures of these three aldehydes are shown in Figure 12.21. The aldehyde vanillin, introduced at the beginning of this chapter, is the key flavoring molecule derived from the vanilla orchid. You may have noticed that vanilla seed pods and vanilla extract are fairly expensive. Imitation vanilla flavoring is less expensive because it is merely a solution of the compound vanillin, which is economically synthesized from the waste chemicals of the wood pulp industry. Imitation vanilla does not taste the same as natural vanilla extract, however, because in addition to vanillin many other flavorful molecules contribute to the complex taste of natural vanilla. Many books made in the days before acid-free paper smell of vanilla because of the vanillin formed and released as the paper ages, a process that is accelerated by the acids the paper contains. 

The high demand for authentic vanilla extract as a flavoring agent has resulted in frequent attempts at adulteration. An HPLC method for the quantitation of coumarins as an adulterant in a variety of vanilla flavorings, using a 10-yu.m /xBondapak Cl8 column with MeOH-HzO (40 60, v/v) as the mobile phase, was proposed (156). Phenolic analysis could be used further for the detection of mixtures of fruits in jams (157). The phenolics present in different commercial jams of apricot, plum, peach, strawberry, sour orange, apple, and pear have been compared and the characteristic compounds for each different jam identified for potential use as marker compounds. 

Vanillin is one of the widely used flavoring compounds adopted in the food industry. Naturally, it is obtained from Vanilla planifolia, largely cultivated in the tropical area. Vanilla can be synthesized by different... 

Tripathi, U., Rao, S.R. and Ravishankar, G.A. (2002) Biotransformation of phenylpropanoid compounds to vanilla flavor metabolites in cultures of FJaematococcus pluvialis. Process Biochemistry 38(3), 419 426. 

A review of HPLC techniques which have been used to study flavors in a wide variety of foods and flavorings is presented. Specific examples of how HPLC has been used to study nonvolatile flavor compounds 1n beer, beef, tea, grapefruit juice, vanilla, soy bean etc., are presented. Relative advantages and disadvantages of using HPLC vs GLC are discussed. 

There has been much work conducted recently in the area of plant cell culture, or phytoproduction, especially where the product is a plant-unique mixture of Individual flavor substances such as vanilla extract of which vanillin is the major component. As well, the possibility of genetically engineering improved varieties of plants for high yield and consistent quality products is of considerable interest especially for more complex plant-unique flavors. Many flavor compounds are secondary metabolites for which a detailed understanding of their production is not well understood. Presently more knowledge exists In microbial metabolism relative to plant biosynthetic pathways and therefore has resulted in more successful development of microbial-based flavor bioprocessing. As well, scale-up of microbial cultures and isolated enzymes has become relatively common practice while the translation of plant cell culture to large commercial scales is not yet well established. This review will focus on the microbial whole cell and isolated enzyme systems for flavor production. 

Dried vanilla bean sections were subjected to ballistic heating in a short-path thermal desorber, and the volatiles so obtained were analyzed by GC and GC-MS. Over 60 flavor compounds, 18 of them phenolics, were detected by this technique. The method is... 

Impact compound. The name for flavor compounds that decisively influence the character of an aroma or flavor, e.g., (-)- carvone in spearmint oil, citral in lemon oil, filbertone in filbert flavor, or vanillin in vanilla. For further examples, see literature. Lit. J.Food Sci.29, 158ff. (1964) Maarse.p. 237,292,456. 

Formaldehyde is probably the best-known carbonyl compound. Large quantities are made into polymers such as Bakelite, Formica, and Melmac. Since formaldehyde has been cited as a probable carcinogen, its use in preserving biological specimens has virtually vanished. Acetaldehyde (ethanal) is used in manufacturing organic compounds such as acetic acid and ethyl acetate. Other aldehydes you have probably encountered are benzaldehyde (almond flavor), cinnamaldehyde (cinnamon flavor), and vanillin (vanilla flavor) (Fig. 21.26). 

There are situations where the inclusion of an oil phase does not significantly change the perceived flavor, only the flavor intensity. These situations exist when flavor character is carried by a small number of aroma compounds that have similar oiliwater partition coefficients. One may consider vanilla flavor in this category. Vanilla flavor is largely carried by vanillin and ethyl vanillin (artificial vanilla flavors). These two compounds have similar stractures and thus partition similarly. If one changes the fat content of an ice cream, for example, the vanilla character may change slightly but is seldom a problem. One simply increases the amount of flavor used as the fat content is increased. 

Ethyl vanillin is a closely related compound, 3-ethoxy-4-hydroxy-benzaldehyde, which is not found in nature but is prepared synthetically from safrole. It has an intense vanilla-like odor and is about three to four times more powerful than vanillin as a flavoring agent. Like vanillin, it is widely used in the preparation of imitation vanilla flavorings but can give a somewhat harsh chemical character in higher dosage levels. In practice, a maximum of 10% of vanillin may be replaced by ethyl vanillin without this objectionable note being obvious. 

The simplest and surest application of GC-MS methodology is to search for nonnatural compounds in a flavor. For example, ethyl vanillin, allyl caproate, and ethyl maltol do not exist in nature so their presence in a flavoring (e.g., ethyl vanillin in a vanilla flavor, allyl caproate in a pineapple flavor, and ethyl maltol in a sweet... 

The vanillin in the mixture is not a natural product. Natural vanilla extract is a mixture of hundreds of compounds in addition to vanillin. Artificial vanilla flavoring is a solution of pure synthesized vanillin, 4-hydroxy-3-methoxybenzaldehyde. Mixtures of vanillin with other toxicants enhance mutagenic effects [29] and produce synergistic inhibition of hgnoceUulose degradation when mixed with catechol [30]. 

Aldehydes and ketones often have characteristic and recognizable odors. For example, 2-heptanone is a liquid with a dove-like odor that accounts for the odors of many fruits and dairy products. Some aldehydes and ketones find use as flavoring agents. For example, vanillin, the compound responsible for vanilla flavor, is an aldehyde. Alpha-demascone and 2-octanone are ketones responsible for berry and mushroom flavors, respectively. Butanedione, shown in the margin, is a yellow liquid with a cheese-like smell that gives butter its flavor. 

Because it does not have quite the same taste as the much more complex mixture of compounds found in natural vanilla extract, it is most often used with stronger flavors and scents such as chocolate, cloves, nutmeg, or cinnamon. 

Ethyl vanillin is a synthetic compound that is three and a half times stronger in flavor than real vanilla, although the flavor is not quite the same. Because it is less expensive and keeps better during storage and transport, ethyl vanillin is used as a substitute for vanilla in foods and perfumes. 

The long fermenting process converts several glucosides into glucose, vanillin, and other complex aromatic flavors. The vanilla beans can be further processed by extracting soluble compounds in ethanol and water mixtures, resulting in vanilla extract. 

Romagnoli LG, Knorr D (1988) Effects of ferulic acid treatment on growth and flavor development of cultured Vanilla planifolia cells. Food Biotechnol 2 93-104 Schrader J, Etschmann MMW, Sell D, Hilmer J-M, Rabenhorst J (2004) Applied biocatalysis for the synthesis of natural flavour compounds—current industrial processes and future prospects. Biotechnol Lett 26 463-472... 

Classify the following as element, compound, or mixture, and justify your classifications salt, stainless steel, tap water, sugar, vanilla extract, butter, maple syrup, aluminum, ice, milk, cherry-flavored cough drops. 

Salt, sodium chloride classification compound. Stainless steel, mix of iron and carbon classification mixture. Tap water, dihydrogen oxide plus impurities classification mixture. Sugar, chemical name sucrose classification compound. Vanilla extract, natural product classification mixture. Butter, natural product classification mixture. Maple syrup, natural product classification mixture. Aluminum, metal classification in pure form—element (sold commercially as a mixture of mostly aluminum with trace metals, such as magnesium). Ice, dihydrogen oxide classification in pure form—compound when made from impure tap water—mixture. Milk, natural product classification mixture. Cherry-flavored cough drops, pharmaceutical classification mixture. 

Sostaric, T., Boyce, M.C. and Spickett, E.E. (2000) Analysis of the volatile compounds in vanilla extracts and flavorings by solid-phase microextraction and gas chromatography. Journal of Agricultural and Food Chemistry 48, 5802-5807. 

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