Oranges aroma

The oils have a high terpene hydrocarbon content (>90%, mainly (+)-limonene), but their content of oxygen-containing compounds differs and affects their quality. Important for aroma are aldehydes, mainly decanal and citral, and aliphatic and terpenoid esters. The sesquiterpene aldehydes a-sinensal [17909-77-2] and/3-sinensal [6066-88-8], which contribute particularly to the special sweet orange aroma, also occur in other citrus oils, although in lower concentration [369-370a, 370d, 394,421, 430-438]. 

The consensus aroma description of the Valencia essence oil was that of a prominent, sweet, pleasant orange aroma. It also possessed warm, spicy, fatty and green undertones. In comparison, the aroma of the Early-Mid essence oil was described as green, fruity and fatty with a weak orange character. Both oils were produced at the same commercial facility, using identical equipment and procedures during the same season. Therefore, any observed differences should be solely due to the composition of the respective cultivars. In Florida, early and mid season oranges are primarily from Hamlin, Pineapple and Parson Brown cultivars. 

Fig. 4.14. Scores plot on the first three PCs for a set of natural orange aroma samples described by GC-MS data. Different samples are indicated by the letters A-P, and different categories by different symbols (from Lin etal. 1993 with permission of Elsevier Science).

By application of these substrates, some of which were characterized by a distinctive odor, exclusively the terminal 4-oxysubstituted 3-methylbutyraldehydes yielded. The cumyl-derived aldehyde was converted into the primary alcohol by using NaBH,j [186]. The alcohol showed a nutty woody ozoney, fresh air cloth, and green-orange aroma profile. 

Nahon, D.F., PA. Navarro y Koren, J.P. Roozen, M.A. Posthumus, Flavor release from mixtures of sodium cyclamate, sucrose, and an orange aroma, J. Agric. Food... 

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