Volatile flavor derivation

A tree, Scorodocarpus borneensis, native to Borneo and the Malay peninsula, has a garlic-like smell and is known as wood garlic . The fruit is used locally for seasoning. The major volatile flavor compounds from wood garlic are similar to those of garlic itself. Some of these materials are polysulfur compounds and have antimicrobial activity against some bacteria and fungi. These materials contain four sulfur atoms.75 They are either 2,4,6-trithiaheptane-5-thione-2,2-dioxide (CH3-SO2-CH2-S-CS-S-CH3) or derivatives of tetrathia-octane (CH3-S-CH2-S-S-CH2-S-CH 3, CH3-SO2-CH2-S-S-CH2-S-CH3, CH3-S-CH2-SO2-S-CH2-S-CH3). 

Table 2. Terminating Retro-Aldol Derived Volatile Flavor from Various Alpha/Beta Unsaturated Carbonyl Generating Precursors...

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... 

Many varieties of red pepper, derived from plants of the genus Capsicum, are used in different cuisines around the world for their sensory properties of oral chemical "heat", volatile flavor and color. Determination of the degree of heat in a pepper sample has been a difficult problem for both sensory and instrumental analysts of flavor. Furthermore, the literature concerning the sensory physiology and perceptual responses of the "common chemical sense" (as defined later) has lagged behind other areas of study of the chemical senses. The purpose of this paper will be to review recent developments in two areas, the development of a standard method for sensory analysis of ground red pepper heat and the psychophysical characterization of observers responses to oral chemical Irritation induced by spice-derived compounds. 

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),... 

Complex volatile hquids derived from flowers, stems, and leaves, and often the entire plant. They contain terpenes (pinene, dipentene, etc.) and are used chiefly for perfumery and flavorings. Usually resinous products are admixed with them. Turpentine is a highly resinous essential oil. 

Moller, J.K.S., Hinrichsen, L.L., and Anderson, H.J., Formation of amino acid (L-leucine, L-phenylalanine) derived volatile flavor compounds by Moraxella phenylpyruvica and Staphylococcus xylosus in cured meat model system, Int. J. Food Microbiol., 42, 101, 1998. 

Acid lability. Several of the polyols although odorless, are acid labile and readily form volatile flavorants at ambient temperature and juice pH (18,28,29) Hotrienol, for example, appears to be formed wholly by acid catalyzed dehydration of dienediol 30a (26,30). Four naturally occurring hydroxyllnalool derivatives l.e. 29,30a,31 and 32 were heated for 15 min at 70°C and pH 3.2 and thirteen volatile monoterpene products (l.e. la,5,6a,9,10,11,12,15, 16,17,18,21 and 22) were identified by headspace analysis (18). 

Yeast extracts represent an important source of volatile sulfur compounds, many of which possess low odor threshold values. They are used as sources of flavor for a range of savory foods, especially when a meaty note is required. In spite of the usefulness of yeast extracts, there are very few reports of their volatile flavor components. The production of yeast extracts is briefly reviewed, and the volatile sulfur compounds which have been identified are discussed. A recent study is presented in which the aroma components of some yeast extracts were analyzed. A total of 268 compounds were identified, including 67 sulfur compounds. The 34 sulfur compounds reported for the first time comprised 3 aliphatic sulfur compounds, one sulfur-substituted benzene derivative, 10 thiophenes, 18 thiazoles and 2 alicyclic sulfur compounds. Their importance as components of flavors and routes to their formation are considered. 

The studies published in this promising area of flavor chemistry and physiology have been limited to a few volatile compounds. They need to be extended to the multitude of other volatile compounds derived from lipid oxidation. Many of these volatiles are known to have a significant impact on quality and acceptability of lipid-containing foods. The complex volatiles produced by food lipids containing n-3 polyunsaturated fatty acids reported to impart nutritional and health benefits are especially important because they develop undesirable fishy odors and flavors at extremely low levels of oxidation (Chapter 4.D Chapter 5.F Chapter ll.E). 

Recent studies of photooxidized butter and butter oil identified by aroma extract dilution analysis, 3-methylnonane-2,4-dione, a potent volatile compound derived from furanoid fatty acids (see Section C.4) (Figure 11.7). Six different furanoid fatty acids were established as dione precursors, and were found in various samples of butter made from either sweet cream (116 76 mg/ kg), or from sour cream (153-173 mg/kg), or from butter oil (395 mg/kg). Similar precursors of the dione were identified in stored boiled beef and vegetable oils. This flavor defect arising by photooxidation of butter or butter oil is apparently different from the light-activated flavor in milk,that involves the interaction of sulfur-containing proteins and riboflavin. However, more sensory comparisons are needed to distinguish between these two flavor defects due to light oxidation. 

Volatile flavor compounds may be formed from lipids via several different pathways. The primary pathways include a- and P-oxidation, and oxidation via lipoxygenase enzymes [8,9]. Some of the earliest work in this area was on the development of banana aroma by Tressl and Drawert [10]. Recent work showing pathways for the formation of several key volatiles derived from apple lipids are illustrated in Figure 4.2. They demonstrated the conversion of labeled acetate to acetate esters and labeled butanoate to butanoate esters by postchmacteric banana slices. They have further shown the conversion of hexanoic acid to hexanol by these tissues. 

There is little in the literature on the effect of plant age on the development of volatile flavor components, however Freeman [70] has reported on flavor formation during onion seed germination and growth. It appears that after approximately 20 days, onion flavor potential is completely developed. The seed itself contains no flavor precursors (cysteine sulfoxide derivatives) and only about 3% the aUiinase activity (enzyme) of mature onion bulbs. However, the plant quickly develops alliinase activity and a maximum activity is reached after 15-20 days. Therefore, flavor is developed well before the plant is of suitable size for consumption. 

Flavor and aroma of fruit and scent of flowers is represented by a mixture of dozens of volatile components [160, 161]. Most of these volatiles are derived from three chemical groups, namely isoprenoids, phenylpropanoids and aliphatics. Several volatiles in the mixture will have a dominant effect on the overall fruit aroma or flower scent that is independent from their relative levels. Namely, trace levels of a certain component might have a substantial effect on the typical aroma and scent associated with a particular fruit or flower. Due to promiscuity of enzymes associated with volatile compounds metabolism, a relatively large number of volatile components could be altered by modifying a single gene. For instance, overexpression of the ( )-j3-caryophyllene synthase from rice in Arabidopsis results in emission of a bouquet of terpenoid volatiles, including (EyP-caryophyllene, j8-elemene and a-humulene... 

Spices and herbs have been used as food additives since ancient times, both as flavoring agents and as natural food preservatives. Essential oils, odorous and volatile products derived from plants, have found a considerable range of applications. They are used mainly as flavors and fragrances in food and perfumery industries. However, due to their antimicrobial activity essentials oils are also important for food and cosmetic preservation and for the control of human, animal and plant diseases that are of microbial origin. 

ESSENTIAL OILS Volatile oils derived from plants and usually carrying the essential odor or flavor of the plant used.. Aluminum alloy equipment has been used in the preparation, storage,. and transport of essential oils. See also Ref (1) p. 131, (2) p. 255. (3) p. 239,... 

Capillary gc/ms, hplc, nmr, ir, and uv are all analytical methods used by the terpene chemist with a good Hbrary of reference spectra, capillary gc/ms is probably the most important method used in dealing with the more volatile terpenes used in the davor and fragrance industry (see Flavors and spices). The physical properties of density, refractive index, boiling point, melting point of derivatives, and specific rotation are used less frequendy but are important in defining product specifications. 

Selecting an approach Off-flavors are typically due to volatile compounds present at extremely low levels. (Flavor is sensed more by the olfactory system than the tongue, which senses only 5 flavors, sweet, sour, bitter, salty, and umami). GC is ideal for detecting low levels of volatile components. In this case, headspace GC will allow you to treat the plastic directly. Since the off-flavor is suspected to be derived from the polypropylene packaging material, you decide to compare different samples ( good vs. bad ) of the material using headspace GC with both a flame ionization detector (FID) and a sniff port. These chromatograms are shown in Fig. 21.9. 

Here are the key points. First, the most abundant volatiles in tomatoes are derived from catabolism of essential fatty acids. Linoleic acid is the precursor for hexanal and linolenic acid is that for cw-3-hexenal, cH-3-hexenol, and trans-2-hexenal. All of these are important flavor elements in the tomato. A healthy diet for people requires... 

Few of the phenol derivatives that have a keto substituent in their side-chain are of interest as fragrance or flavor substances. A number of phenols and phenyl ethers acetylated in the benzene ring have been identified as volatile components of foods. 4-Methoxyacetophenone is of some interest as a fragrance material. 4-Hydroxybenzylacetone, a higher mass phenol ketone, has a characteristic raspberry aroma. 

The main volatile constituent of all three products is linalool (in neroli oil 28-44%). Their typical flavor is created by a number of nitrogen-containing trace constituents, such as indole and derivatives of anthranilic acid [428, 643, 644]. 

Viability of Starch Derivatives as Flavoring Encapsulants. The capillary GC vapor phase flux term (defined by a percent external standard or ZEStD flux) previously described (34) was used to screen starch derivatives (oxidized, dextrinized and/or covalent amino acid linkage) as to their flavor encapsulation potential. The samples were prepared as previously described (34) with the exception of an added reduced pressure deaeration step, thus allowing the use of the headspace diffusivity versus retention standard curves to predict volatile lemon oil retention following spray drying. 

The aromatic, warm, and sweetish odor and taste of the seed, leaves, and stem arises from the presence of a volatile oil that contains anethole p-propenyl phenylmethyl ether, C3H5C6H4OCH3), the derivatives of which (anisole and anisaldehyde) are used in food flavoring, particularly bakery, liqueur, and candy products, as well as ingredients for perfumes. For commercial production of anise oil, the seeds and the dried, ripe fruit of the plant are used. Anise oil. a colorless to pale-yellow, strongly refractive liquid of characteristic odor and taste, is prepared by steam distillation of the seed and fruit. The oil contains choline, which finds use in medicine as a carminative and expectorant. 

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