Myrcene orange

Poncirus trifoliata Rafin Gou Gi (Trifoliate orange) (fruit) Poncirin, limonin, imperatorin, bergapten, neohesperidin, citrifoliol, myrcene, camphene, gamma-terpinene.33 Treat gastric pain, constipation, and prolapse of the uterus or rectum. 

The odour intensities of volatiles showing similar odour qualities are partially additive [68]. To substantiate such additive effects, three groups of odorants (terpene hydrocarbons, esters or aldehydes) were omitted from the aroma model for orange juice. For all groups, a significant difference from the complete model was observed (Table 6.39). Omission of esters nos. 12,14 and 15 with ethyl butanoate (no. 13) still present was clearly detectable. This indicates that the fruity quality in the odour profile is enhanced by additive effects. In contrast, no difference was perceivable when (R)-a-pinene (no. 17) and myrcene (no. 18) were omitted. The concentration of the odorants in juice differs depending on the variety. Thus, the weaker citrus note of Navel oranges compared with the above discussed variety Valencia late is due to a 70% lower content of (R)-limonene [67]. 

Figure 1. Vapor pressure vs. temperature curves of important components of orange essential oil (0 0) a-pinene, ( - ) d-limonene, ( A - A ) myrcene, ( o - o ) linalool, ( - ) a-terpineol, ( - ) decanal, ( A - A ) a-citral (Data from (38)).

Farnworth et al. (2001) found that in Mexican orange juice the concentrations of acetaldehyde and ethyl acetate were higher in unpasteurized juice. a-Pinene, p-myrcene, limonene, a-terpineol, 1-hexanol, 3-hexen-l-ol, and sabinene concentrations were higher in the unpasteurized juice than in the pasteurized juice. 

Monoterpenes are important constituents of essential oils. These complex mixtures of compounds, as well as individual monoterpenes are used in medicine (F 2) and industry (F 4). Commercially important monoterpenes are, for instance, menthol, camphor, carvone, thymol, fenchone, and oc-pinene. Monoterpenes flavor foodstuffs and beverages (F 1). Citral, for example, is an important constituent of the smell of lemon. Thymol is involved in the flavor of mandarin oranges. Other monoterpenes, e.g., limonene and geraniol, are constituents of flower scents and attract plant pollinators (E 5.5.1). High monoterpene concentrations in plants will repel most potential predators, but my attract some animals (E 5.5.3). Animals use citronellal, citral, and oc- and jS-pinene als feeding deterrents (E 5.1) and geraniol, geranyl esters, myrcene, and terpinolene as pheromones (E 4). Some monoterpenes, e.g., 1,8-cineole and camphor, are also involved in plant-plant interactions (E 5.3). 

Several Citrus EOs contain high proportions of limonene (14) as its major component. Orange peels are used as sedative in several countries, and EOs obtained from Citrus aurantium L. (Rutaceae) fruit peels can contain as much as 97.8% of limonene (14). The anxiolytic and sedative properties of Citrus EO suggested by traditional uses have been assessed in mice (Carvalho-Freitas and Costa 2002 Pultrini et al. 2006) and also shown in a clinical setting (Lehrner et al. 2000). The relaxant effects observed in female patients in a dental of ce were produced with a C. sinensis (L.) Osbeck (Rutaceae) EO composed of 88.1% limonene (14) and 3.77% myrcene (15). 

The volatile oil (bitter orange oil) contains more than 90% monoterpenes (main f-limonene, also myrcene, campherr pinene, ocimene, p-cymene, etc.) small amounts of alcohols (linalool, terpinene nerol, farnesol, nerolidol, octanol, etc. usually 0.5-1% aldehydes (mainly decanal also nonanal, dodecanal, citronellal, neral acetaldehyde, formaldehyde, etc.), and ketones (carvone, a-ionone, and jasmine) free acids (octadeca-dienoic, pelargonic, cinnamic, acetic, etc.) about 2.4% esters (linalyl acetate, decyl pe-largonate, octyl acetate, geranyl acetate, etc.) coumarins (osthole and auraptenol) and others (jiangsu list and horhammer). 

The theory of SPME for headspace applications has been described in many publications. Some studies described conditions for measurement of citrus volatiles, particularly referencing d-limonene. Headspace extraction efficiencies of different fibers for some flavors were compared with the correct recognition that mixtures in water were within the solubility limits [5]. Another study concluded that SPME effectively measured head-space volatiles (e.g., d-limonene, myrcene, pinene, and terpinene) of centrifuged orange juice however, these authors did not report the actual concentrations of compounds in the whole juice [6]. Not knowing a compound s juice concentration prevents quantitative measurement of the partitioning among the complex system matrices of fiber, headspace, juice, and pulp. 

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