Green odour

The antennal olfactory receptor system in several phytophagous insects is very sensitive in the detection of the green odour components. In the Colorado beetle Leptinotarsa decemlineata, the threshold of response for trans-2-hexen-1-ol is circa 10b molecules per ml of air (17). In comparison, at 760 mm Hg and 20 C, 1 ml of air contains about 1019 molecules. The insects tested i.e., the migratory locust Locusta migratoria, the carrot fly Psila rosae (18), the cereal aphid Sitobion avenae (19), the Colorado beetle L. decemlineata (17), Leptinotarsa... 

The proportions of the individual green odour components in the leaf odour constitute a chemical message which, when perceived, directs the motor patterns of this insect. The... 

Elderberry (Sambucus nigra) is cultivated on small scale in Europe. The fruits have a high concentration of red and purple anthocyanins and a relatively low concentration of sugars, organic acids and aroma compounds, which make this juice attractive as a natural colour ingredient in other red fruit products [126-129]. The fresh green odour of elderberry juice is associated with volatile compounds with typical green notes such as 1-hexanol, 1-octanol, (Z)-3-hexen-l-ol, ( )-2-hexen-l-ol, hexanal and ( )-2-hexenal, whereas the floral aroma is mainly due to the presence of hotrienol and nonanal [127-130]. 

Lipoxygenases play an important role in determining oil quality. The aromas typical of olive oil are due to complex mixtures of volatile compounds those especially abundant are saturated and unsaturated six carbon atom aldehydes, alcohols, and the esters of alcohols, the cited aldehydes and alcohols having sensory properties responsible for the so-called green odour (Hatanaka, 1996). 

OD-R (floral, herbal) [major damaged leaf green odour insect herbivore attractant]... 

Brassica oleracea (Brassicaceae) [leaf] Solanum tuberosum (potato) (Solanaceae) [leaf, green odour ]... 

The key odorants of two olive oils, I and S, with very different odour profiles (Table 6.36) are listed in Table 6.37. The apple-like and green odour qualities, which are characteristic for oil I, are caused by aldehydes nos. 5 to 7 and 15 (Table 6.37). Their concentration is higher in oil I than in S. The very potent odorant no. 10 occurred only in oil S. As a result of its high OAV and its blackcurrant-like odour quality, it is the character impact odorant of this oil [64, 65]. 

The concentrations and OAV of odorants detected in strawberry juice are given in Table 6.41. To confirm that these compounds are actually the key aroma compounds, they were dissolved in a model juice matrix of pH 3.5 [75]. Sensory evaluations showed that the intensities of the fruity, sweet and green odour notes of the model were nearly as high as those of the natural juice. Only the fresh strawberry note was somewhat lower in the model. 

Hatanaka, A., The biogeneration of green odour by green leaves, Phytochemistry, 34, 1201, 1993. 

A small number of hemiterpenes are used in perfumery, the most important of which are prenyl acetate and benzoate. Thioesters, such as those shown in Scheme 4.11, have extremely intense green odours reminiscent of galbanum, in which they occur naturally. The esters are usually prepared from prenyl chloride and the thioesters from the corresponding thiol and acid chloride. 

Constit. of seed oil of Lindera obtusiloba and other members of the Lauraceae. Not found in any other family. Liq. with fatty/green odour. Bp 13 148-150°. 4-Bromophenacyl ester Mp 43.3°. 

Biogeneration of Green Odour Emitted by Green Leaves - On HPO Lyase and Relationship of LOX-HPO Lyase Activities to Environmental Stimuli. K, Matsui, T, Kajiwara and A, Hatanaka. 

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