Grapefruit peel oils

TABLE 1. Average Values for Physical and Chemical Properties of Cold-pressed Red and White Grapefruit Peel Oils. 

Chatterjee, A., R. N. Rej, A. Banerji, and J. Banerji Abnormal Rearrangement of Isoprenoid Epoxide Synthesis of 7-Methoxy-8-(2 -formyl-2 -methylpropyl)-couma-rin, the Lactonic Constituent of Grapefruit Peel Oil of Citrus decumana Linn. (Rutaceae). Chem. and Ind. 1976,410. 

The eremophilane derivative (-h)-nootkatone (195) has been valued for its most important contribution to the distinctive flavor of many citrus oils, in particular of grapefruit peel oil Citrus paradisi, Macfayden) 371, 372). Qualitative 211, 313, 453, 591) and quantitative 38, 211, 313, 591, 630) aspects of this aroma compound have been treated. The naturally occurring (-h)-nootkatone (195) is detectable at 1 ppb in water (33). The both enantiomeric forms of ketone (195) differ not only... 

In an example provided by nootkatone, an essential aroma compound of grapefruit peel oil (cf. 18.1.2.6.3), it is obvious that the two enantiomers (optical isomers) differ significantly in their aroma intensity (cf. 5.2.5 and 5.3.2.4) and, occasionally, in aroma quality or character. 

C15H22O, Mr 218.33, mp 35 °C, has been isolated from grapefruit peel and juice and identified in other citrus oils as well. The commercially available product is a colorless to yellowish liquid with a typical grapefruit odor. 

Nootkatone is an important constituent from grapefruit flavour. It is synthesised by oxidation of valencene, which is obtained and isolated from orange peel oil where it occurs at a maximum level of 0.4% [9]. 

Citrus peel oils of very complex composition are contained in oval, balloon-shaped oil sacs, or vesicles, located in the outer rind, or flavedo, of the fmit (3). The oil is usually extracted by mechanical separation or hydrodistUlation. The five main types of citrus from which peel oils are recovered are orange, grapefruit, tangerine, lemon, and lime (4). Mechanical separation, known as cold-pressing of peel oils, does not use heat in order to avoid loss of volatile components. Swisher and Swisher (1) described three general commercial methods that are widely used in citrus industry to extract crude oils from fruit peels ... 

Typical bitter grapefruit note which resembles both bitter and sweet orange. Additionally, the peel oil is characterised as a peel-like, pronounced, watery, juicy, greenish citrus note. 

The taste of grapefruit juice is acid, fruity, bitter sweet. The peel oil has a characteristic terpeny, woody, exotic fruity character. 

Citrus paradisi Citrus paradisi extract. See Grapefruit (Citrus grandis) extract Citrus paradisi peel oil. See Grapefruit (Citrus grandis) oil... 

Synonyms Citrus grandis oil Citrus paradisi peel oil Grapefruit oil Shaddock oil... 

Coumarins Silica gel and Cl 8 Hexane and Rio red acetone water and grapefruit peels methanol and oil [89]... 

Grapefruit oil is obtained by cold pressing of the outer peels of the fruits of Citrus paradisi Macfad. (Rutaceae). It is a greenish-yellow liquid, with an odor resembling that of sweet orange oil, but more herbaceous and bitter. 

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