Phenolic flavor

Ha, J.K., Lindsay, R.C. 1991. Contributions of cow, sheep, and goat milks to characterizing branched-chain fatty acid and phenolic flavors in varietal cheeses. J. Dairy Sci. 74, 3267-3274. 

There are also other alterations of the same origin that produce other flavor defects - a very strong phenol flavor produced by the resin monomers or impurities (cresols, phenol, 2-ethylphenol, 3-ethylphenol, m-terbutylphenol (Fig. 10.2), 2,4-dichlorophenol, etc.). 

Separation of the phenolic flavor components, carvacrol and thymol, from oregano leaves. 

Tressl etal. (1976) and Fiddler etal. (1967) identified it as a decomposition product of ferulic acid (H.87). The odor is mild and sweet, deep-floral, very tenacious with great warmth and resemblance to carnation, sweet william or wallflower (Arctander, 1967). The ( )-isomer has a smoky, phenolic flavor and the (Z)- sweet, eugenol-like (Chemisis, 1965). 

The compound has a very sweet odor of rather gassy-pungent character when undiluted, becoming floral-sweet, heavy, when diluted (Arctander, 1967). It is also characterized as having a tobacco, very powerful, heavy, tenacious odor (Chemisis, 1988), and a burnt, fatty, floral, phenolic flavor (Chemisis, 1973). 

Wheat beers utilize raw or malted wheat, rather than malted barley, as their primary raw material base. Fermentation may be spontaneous (natural flora of the brewery, Belgian Lambic beers [see below]) or with a top fermentation yeast strain. South German wheat beers (weissbier) utilize a top fermenting yeast strain that produces a characteristic phenolic flavor (4-vinyl-guaiacol, dove-like see Table 18.3 Anderson et al., 2000 McMurrough et al., 1996 Stewart Russell, 1998 Vanbeneden, Gils, Delvaux, Delvaux, 2008). Certain wild yeasts can produce phenohc off-flavors in nonwheat beer styles and as such would be regarded as contaminants. 

Fig. 10.1.12. Phenolic flavor and fragrance components from turpentine...

The unsaponifiable fraction of olive oil contains a variety of minor components including tocopherols (mainly a-tocopherol, in amounts from 12 to 25 mg/100 g), phenols, flavor compoimds, hydrocarbons, and sterols, Ohve biophenols (OBPs, which are inaccurately referred to as polyphenols in some cases) are used as flavorants, colorants, and antioxidants. The best known olive oil phenols are hydroxytyrosol, tyrosol, oleiuopein, apigenin, and luteolin, in both free and derivative forms,... 

When making vanillin from guaiacol the chemist can smell success because the product will have an intense vanilla odor. One can even flavor cookies with the stuff (true ). This Riemer-Tiemann method is also an excellent way to get salicylal-dehyde from phenol in yields of up to 50%. The chemist does everything the same except uses NaOH instead of KOH. 

Hypochlorite readily chlorinates phenols to mono-, di-, and tri-substituted compounds (163). In wastewater treatment chlotophenols ate degraded by excess hypochlorite to eliminate off-flavor (164). Hypochlorite converts btomoben2ene to cb1oroben2ene in a biphasic system at pH 7.5—9 using phase-transfer catalysts (165). 

Nearly all of the benzal chloride produced is consumed in the manufacture of benzaldehyde. Benzaldehyde (qv) is used in the manufacture of perfume and flavor chemicals, dyes, and pharmaceuticals. The principal part of benzotrichloride production is used in the manufacture of benzoyl chloride (see Benzoic acid). Lesser amounts are consumed in the manufacture of benzotrifluoride, as a dyestuff intermediate, and in producing hydroxybenzophenone ultraviolet light stabilizers. Benzotrifluoride is an important intermediate in the manufacture of herbicides, pharmaceuticals, antimicrobial agents, and the lampreycide, 4-nitro-3-(trifluorometh5l)phenol [88-30-2]. 

Phenols occur widely throughout nature and also serve as intermediates in the industrial synthesis of products as diverse as adhesives and antiseptics. Phenol itself is a general disinfectant found in coal tar methyl salicylate is a flavoring agent found in oil of wintergreen and the urushiols are the allergenic constituents of poison oak and poison ivy. Note that the word phenol is the name both of the specific compound hydroxybenzene and of a class of compounds. 

This group of ingredients has many useful properties. Alcohols and phenols are very common in household products. Alcohols are good solvents and are used in perfumes and flavorings to dissolve fats and oils. Heavier alcohols with long chains of hydrocarbons act as emulsifiers and surfactants, bringing oil and water together. 

In a phenol, a hydroxyl group is attached directly to an aromatic ring. The parent compound, phenol itself, Cr,HsOH (4), is a white, crystalline, molecular solid. It was once obtained from the distillation of coal tar, but now it is mainly synthesized from benzene. Many substituted phenols occur naturally, some being responsible for the fragrances of plants. They are often components of essential oils, the oils that can be distilled from flowers and leaves. Thymol (5), for instance, is the active ingredient of oil of thyme, and eugenol (6) provides most of the scent and flavor of oil of cloves. 

Phenolic acids and polyphenols are natural plant constituents which impart flavor and textural components to beverages made from these plants. In order to better understand the role of these easily oxidized compounds in the flavor and stability of beverages, it is necessary to determine them at the low concentrations they occur. LCEC has been shown to be quite effective at these trace determinations... 

The use of copper and iron for coffee brewing equipment produces a dark color and an off flavor, presumably as a result of their interaction with coffee phenols. Aluminum is frequently used for brewing equipment but it has the disadvantage of being dissolved into the brew.31 32 American home percolators made from aluminum do corrode. 

Methods for the decaffeination of green coffee beans, mainly with solvents after a steaming, have already been described. Even with the selective adsorption techniques to remove only caffeine, it is unlikely that the full character of the starting beans can be realized in a final decaffeinated beverage the result is that Robusta coffees are generally used to prepare decaffeinated coffee. The cost is kept down and the treatment, anyway, reduces any harsh or bitter flavor that the Robusta coffee may have had. The resulting beverage will be relatively caffeine-free, but Robusta coffee will contribute more soluble carbohydrates, phenols, and volatile fatty acids, and much less of the diterpenes found in Arabica coffees. 

Other phenolic compounds of commercial importance include the terpenoids, including mono, di, tri, and sesquiterpenes. While most of these are used as essential oils, fragrances, and flavors in various products, they are toxins in certain species. For example the sesquiterpene lactones of the Centaurea species cause an irreversible Parkinson s-like condition in horses called nigro-pallidal encephalomalacia. This is a lethal condition and the prognosis for recovery is grave in most cases, affected horses should be euthanized before reaching the terminal stages. 

Uses Manufacture of ethylbenzene (preparation of styrene monomer), dodecylbenzene (for detergents), cyclohexane (for nylon), nitrobenzene, aniline, maleic anhydride, biphenyl, benzene hexachloride, benzene sulfonic acid, phenol, dichlorobenzenes, insecticides, pesticides, fumigants, explosives, aviation fuel, flavors, perfume, medicine, dyes, and many other organic chemicals paints, coatings, plastics and resins food processing photographic chemicals nylon intermediates paint removers rubber cement antiknock gasoline solvent for fats, waxes, resins, inks, oils, paints, plastics, and rubber. 

Uses Preparation of sodium and butyl benzoates, benzoyl chloride, phenol, caprolactum, and esters for perfume and flavor industry plasticizers manufacture of alkyl resins preservative for food, fats, and fatty oils seasoning tobacco dentifrices standard in analytical chemistry antifungal agent synthetic resins and coatings pharmaceutical and cosmetic preparations plasticizer manufacturing (to modify resins such as polyvinyl chloride, polyvinyl acetate, phenol-formaldehyde). 

Uses Disinfectant phenolic resins tricresyl phosphate ore flotation textile scouring agent organic intermediate manufacturing salicylaldehyde, coumarin, and herbicides surfactant synthetic food flavors para isomer only) food antioxidant dye, perfume, plastics, and resins manufacturing. 

The importance of the Mediterranean diet led to increased research activity on olive oils, which mainly focused, among other issnes, on phenolic substances becanse of their biological activities and of the fact that virgin olive oils are the only vegetable oils that contain them, while tocopherols are widely distributed in such foods. Phenolic substances are responsible for the typical taste of olive oils, characterized by fruity, bitter, and pungent flavors. 

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