8-Octalactone

OCTAHYDRO-l-NITROSOAZOCINE see OBYOOO OCTA-KLOR see CDR750 7-OCTALACTONE see OCEOOO OCTALENE see AFK250 OCTALOX see DHB400... 

Primus persica (L.) Batsch. Tou Ren (Peach) (leaf, flower, fruit) Malic acid, citric acid, octalactone, leucoanthocyanins, tannins, hexalactone, hectalactone, benzyl alcohol, nonalactone, decalactone, ethanol, hexanol, acetadehyde, benzaldehyde, acetic acid, pentanoic acid, hexanoic acid.50 Astringent, febrifuge, parasiticide, diuretic, sedative, vermifuge. 

The main classes of volatile compounds, which are considered to contribute significantly to the overall flavour are lactones, fatty acids, aldehydes and methyl ketones. As noted earlier, there are very small amounts of hydroxy acids, esterified to triacylglycerols, in milk fat. These act as precursors of flavoursome 7-lactones and 8-lactones. It has been reported that three lactones, 8-octalactone, 8-decalactone and y-dodecalactone, are important flavour components in milk fat (Widder et al., 1991 Schieberle et al., 1993). Siek et al. (1969) identified the short-chain fatty acids, 4 0 and 6 0, as key flavour components of milk fat. However, while they may contribute to the overall flavour of milk fat at very low concentrations,... 

In addition to 3-hydroxy- and 3-acetoxyacid esters, pineapples contain 5-hydroxy- and 5-acetoxyacid esters, y -hexalactone and 6 -octalactone as characteristic chiral aroma constituents (2 ). The capillary GC investigation of R-(+)-PEIC derivatives made it possible, to determine the enantiomeric composition of these components for the first time (Figure 8). 

Wines are biologically aged in old casks which, unlike those used for vintage aging, are rarely emptied or scrubbed. As a result, biologically aged wines contain minimal amounts of lactones from wood such as p-methyl-y-octalactone (Chaton-net et al. 1990) and only in the scales holding the oldest wine. 

The two oak lactone isomers cis- and fran -p-methyl-y-octalactone) were first identified in oak wood by Masuda and Nishimura (1971). They are one of the main volatile components present in the extractible fraction of oak wood. Smdies have revealed the detection thresholds for these two isomers to be 0.092mg/L for the cis isomer and 0.49mg/L for the trans isomer in white wines (Chatonnet 1991). Their aroma has been identified as the source of the typical odour of oak barrel aging and has been described as oak or coconut . 

FeuiUat, R, Moio, L., Guichard, E., Marinov, M., Fournier, N., Puech, J. L. (1997). Variation in the concentration of ellagitannins and cis- and rrani-/i-methyl-y-octalactone extracted from oak wood (Quercus robur L., Quercus petraea Liebl.) under model wine cask conditions. Am. J. Enol. Vitic., 48, 509-515. 

Masson, E., Baumes, R., Le Guemeve, C., Puech, J. L. (2000a). Identification of a precursor of yS-methyl-y-octalactone in the wood of sessile oak Quercus petraea (Matt.) Liebl.). J. Agric. Eood Chem., 48, 4306 309. 

Otsuka, K. I., Sato, K., Yamashita, T. (1980). Structure of a precursor of (i-methyl-y-octalactone, an aging flavour compound of distilled liquors. J. Fermen. Technol., 58, 395-398. 

Sefton, M. A., Francis, I. L., Pocock, K. R, Williams, P. J. (1993). The influence of natural seasoning on the concentrations of eugenol, vanillin and ciT-tTOns-/l-methyl-y-octalactone extracted from French and American oak wood. Sci. Aliments, 13, 629-643. 

We have today a better understanding of the composition of oak of various origins. Oak is a naturally aromatic wood. This is largely due to the presence of a highly aromatic lactone, fi-methyl- -octalactone [1], which is specific to the Quercus genus... 

---