Citrus Flavor. Volatile Constituents of the Essential Oil of the Orange (Citrus sinensis)^a,b

Abstract

SUMMARY Analysis by gas‐liquid chromatography (GLC) of the essential oil from California Valencia oranges revealed over 50 components. A preliminary separation of the intact oil into two major fractions, the terpenes and terpenoids, was made by liquid‐solid chromatographic techniques. Examination of the terpene fraction by GLC revealed 15 constituents, of which a number were tentatively identified. The terpenoid fraction contained some 37 constituents, many of which were tentatively identified. These techniques increased resolution and permitted tentative identification of some 14 compounds not hitherto reported in Valencia orange oil. These compounds arc: 3‐hepten‐l‐ 01; n‐octyl acetate; n‐undecanal; hornyl acetate; isopulegol; n‐decyl acetate; borneol; citronellol; neral; geranyl acetate; α ‐pinene; α ‐phellandrene; γ‐terpinene; and p‐cymene. The constituents were tentatively identified by calculating relative corrected retention volumes and comparing these with values for known compounds. Two stationary liquid phases used yielded data that lend credence to the tentative assignment of identities of the constituents isolated. In addition, infrared examination of some collected fractions made possible partial identification of the compounds.

Analysis of the Flavour and Aroma Constituents of Florida Orange Juices by Gas Chromatographya

“…Work by Bernhard (1960Bernhard ( , 1961 and Clark and Bernhard (1960) Valencia orange oil as related to fruit maturity and presented evidence for the identification of 27 compo-.nents in the terpeneless fraction.…”

Changes in Total Carbonyl Content of Orange Juice and Concentrate During Storage

“…It is rapid enough to yield a total carbonyl analysis and a gas chromatographic trace of the total volatile organic constituents from a frozen sample within a single working day. The utility of the method was demonstrated by the first-reported identification from orange juice on a laboratory scale of several aldehydes known to be constituents of cold pressed orange oil (Stanley et al, 1961 ;Bernhard, 1961) and of commercial orange essence (Wolford et al, 1962). In the exploratory phases of the work it was found that the continuous recycling system of Kolfenbach et aZ.…”

“…Bernhard (1961) reported an orange peel oil to contain over 50 components, of which 10 were carbonyls. Wolford et al (1962) detected a similar number of components in a commercially prepared orange essence.…”

“…Investigations of the composition of coldpressed orange peel oil have been stimulated in recent years by the development of gasliquid chromatography. Bernhard (1961) reported an orange peel oil to contain over 50 components, of which 10 were carbonyls. Wolford et al (1962) detected a similar number of components in a commercially prepared orange essence.…”

Studies on physiologically active substances in citrus peel. Part IX. Structure and hypotensive effect of flavonoid glycosides in orange (Citrus sinensis OSBECK) peelings.

“…8) Crude flavonoids were obtained from a hot water extract of orange peel by the procedure illustrated in Fig. 1.…”