Valencia essence oil

In contrast to Valencia essence oils, the reduced presence of volatile flavour constituents is significant. 

Samples of Early-Mid and Valencia essence oils were obtained from a citrus processing plant in Lake Wales, Florida on three different processing days. The samples were diluted with ethyl ether (1 80) and 20 pL of 2000 ppm of 4-heptadecanone was added as internal standard to 1.0 mL of the diluted oil. A 0.1 uL aliquot was injected into the GC. 

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. 

The desired orange flavor is the result of volatile compounds in specific proportions (Shaw, 1991). There are six major contributors to orange flavor acetaldehyde, citral, ethyl bu-tanoate, d-limonene, nonanal, octanal, and a-pinene with two major types of essence oils, early-mid and Valencia (Shaw, 1991). Early-mid oranges include Hamlin and Pineapple. 

GC-O and GC-FID Comparison between Early-Mid Season and Valencia Orange Essence Oil... 

Figure 1. Comparison ofgas chromatograms (polar separation) of commercial Valencia orange essence oil (lower solid line) and that of Early-Mid orange essence oil (upper dashed line). The Early-Mid essence oil is offset and shifted...

Table 1. Comparison of aroma active components in Valencia and Early-Mid season orange essence oils...

Some of the data is difficult to explain. For example, m-cresol (peak 26) has a pronounced negative aroma character and was found only in the Valencia oil. Despite these difficulties, much of the observed quality differences between Valencia and Early-Mid season orange essence oils can be explained from the lack of positive aroma components in the Early-Mid season oil and the presence in Early-Mid of aroma components which are not particularly positive. 

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