Volatile and odoriferous compounds

Chatonnet, P. (1998). Volatile and odoriferous compounds in barrel-aged wines Impact of cooperage techniques and aging conditions. In A. L. Waterhouse S. E. Ebeler (Eds.), Chemistry of wine flavour, (pp. 180-207). American Chemical Society Washington. 

Volatile and Odoriferous Compounds in Barrel-Aged Wines Impact of Cooperage Techniques and Aging... 

Toasting, or, more precisely, hydrothermolysis , leads to the development of new volatile and odoriferous compounds, mainly (a) furanic aldehydes,... 

Males of neotropical euglossine bees (Apidae), called orchid bees, collect odoriferous substances from flowers of orchids and other plants. The floral scents of these species display relatively simple chemical compositions dominated by one or two major components, mostly terpenoids and aromatic compounds such as cr-pinene, 1,8-cineol, eugenol, -dimethoxybenzene (35), 2,3-epoxygeranyl acetate (36), nerolidol, 4-methoxycinnamaldehyde (37), and benzyl benzoate.113 Since the orchid bees have odor preferences, their collection of fragrances leads to specialized pollination of particular plant species. Male bees absorb the floral volatiles with their tarsal hairs, form species-specific bouquets, and finally accumulate them in their hind tibial pouches. These bouquets have potential roles in courtship displays and marking territories.114 115... 

Deodorizing was developed to remove the relativity volatile odoriferous compounds from the host triglyceride. From the early efforts to boil the volatiles at atmospheric conditions and high temperatures, the modern practice of applying heat under low absolute pressure for a particular period of time has developed. As there is a substantial difference between the vapor pressure of the oil and the volatile materials affecting the flavor, color, and stability, deodorizing can consist of any method to evaporate these substances without damaging the oil. 

The term varietal aroma should not, however, be taken to imply that each grape variety has specific volatile compounds. In fact, the same odoriferous compounds and their precursors are found in the musts and wines of several grape varieties in the same family, as well as other fruits or plants. The individual aromatic personality of wines made from each grape variety is due to the infinitely varied combinations and concentrations of the various compounds. 

Bergstrdm, G., Kullenberg, B. and Stallberg-Stenhagen, S. (1973) Studies on natural odoriferous compounds. VII. Recognition of two forms of Bombus lucorum L. (Hymenoptera, Apidae) by analysis of the volatile marking secretions from individual males. Chem, Scr., 3, 3-9. 

Bergstrdm, G. and Tengd, J. (1974) Studies on natural odoriferous compounds IX. Farnesyl- and geranyl esters as main volatile constituents of the secretion from Dufour s gland in 6 species of Andrena (Hymenoptera, Apidae). Chem, Scr.y 5, 28-38. 

In mixtures such as secretions and scent marks, the polarity of the non-pheromonal compounds may greatly affect the release of the active odor molecules (Regnier and Goodwin, 1977). The pH also affects volatility with higher acidity, a volatile odoriferous base, such as an amine, will form larger amounts of non-volatile salts and, therefore, contribute less to perceived odor. Conversely, odorous acids such as volatile fatty acids will increasingly form salts as the alkalinity increases (Albone, 1984). 

Other fungal, moldy, or earthy defects have been identified in juice made from black and white grapes affected by various kinds of rot. The microorganisms responsible have not always been identified, but a considerable number of odorous zones have been identified by GPC-olfactometry, and some of the odoriferous volatile compounds have also been identified (La Guerche et al., 2003b). 

Cyclodextrins form crystalline inclusion complexes with many organic compounds, including some gases, which are bound within the molecule. Formation of these complexes is called encapsulation. Encapsulation results in a change of the physico-chemical properties of encapsulated compounds (e.g. volatility of flavour-active compounds and their increased stability against oxidation and photodegradation). Cyclodextrins are, therefore, of greatest use as carriers (encapsulators) of odoriferous substances, emulsion stabilisers and are also used to remove bitter substances from citrus juices (see Section 8.3.5.1.1). 

---