Sweet Orange Oil

#### Orange Oil, Sweet, expressed. In quantity produced, the oil of sweet orange ranks number one of all the citrus oils. Lemon oil is a close second, and perhaps even outweighs sweet orange oil if we do not include distilled oil in the world production of sweet orange oils. Expressed sweet orange oil is not truly an essential oil according to our definitions (see **Essential**** ****Oil,**** **Part One of this book). It does contain small amounts of non-volatile matter. It is produced by expression by hand or machine from the peel of the sweet orange, the fruit of **Citrus Aurantium, ***varietas dulcis.* The tree seems to have originated in the Far East in the area between the Himalayas and southwestern China. It came to Europe in the early part of the 16th century, and soon afterwards was brought to the Americas by the Spanish and Portuguese explorers. Seedlings of the tree were “landed” in West Africa by Portuguese seafarers long before it was brought to Europe. Thus the Guinea trees are the descendants of the first shipment of orange trees outside Asia. It is possible, however, that orange trees were brought to Polynesia even before the sixteenth century. Sweet orange oil acquired its name “Portugal oil” for the above reasons. The orange tree grows in numerous varieties all over the world in warm-temperate, semi-tropical and tropical zones. The oil from the peel is expressed in most of these countries, but in many cases only for local use (in carbonated beverages, orangeade, etc.). The main producers for worldwide consumption are: the United States of America (California, Florida, and Texas), Guinea, Cyprus, Italy, Spain, the Union of South Africa, Rhodesia, Brazil, Israel, the West Indies and Algeria. India, Indonesia, China, Japan, Argentina, Greece, Pakistan, etc. produce minor quantities for local consumption. The Japanese sweet orange oil is derived mainly from **Citrus**** ****Aurantium, ***varietas natsudaidai, *a local variety 12 metric tons were produced in *1958 *in Japan. This quantity covers only a fraction of the annual requirements of the Japanese flavor industry. The U. S. A. and Cyprus are the most important producers of modern mechanically expressed oil. while Guinea is the largest producer of hand- pressed oil. Spain specializes in particularly rich- flavored oils, processed in a different way. The total world production of expressed + distilled sweet orange oil exceeds 1,500 metric tons per year. The U.S.A., Guinea, Cyprus, Israel and Brazil will account for 80% of the world production. The technique of production of expressed citrus oils has been the subject of comprehensive works, and readers who may be interested in the detailed description will have no difficulty in finding expert literature on this subject. It should be mentioned at this point, however, that the wide differences among sweet expressed orange oils from various origins are partly due to the differences in expression technique. Machine expression usually yields oils with high evaporation residue while the various hand-expression methods lead to oils with low residue. The amount of residue in an orange oil has no direct relation to the quality of the oil. It may only affect tenacity. but not odor or flavor type. The particularly high content of oxygenated compounds (which are among the most important flavor and perfume materials) in the Guinea oils is probably due to the fact that these oils are expressed from not fully ripe fruits. There are two main types of Guinea sweet orange oil: perfumery oil and flavor oil. The former is a very volatile, light, fresh- smelling oil, the latter is heavy-rich, sweet and yet fresh, powerful in flavor. A small percentage of the Spanish production is the so-called “primera” oil; this is the upper layer from the separators in which the crude oil is matured from the date of expression for a period of a couple of weeks. This “primera” oil is of extraordinarily high flavor value, and is much sought after by flavor houses for use in soft drink flavors, etc. The primera oils are usually lighter in color than ordinary Spanish sweet orange oils. These are distinguished by their very intense, orange-yellow color which may be a drawback in perfumes. Apart from these variations, the sweet orange oils from the same type of fruit from various parts of the world are surprisingly uniform. With strict quality control of the fruits, highly modern machinery, quick packing and proper storage and shipping, oils from far apart sources can be quite similar and are often used interchangeably in perfumery or flavor work. California and Cyprus oils illustrate this fact, the latter perhaps being superior in keeping qualities. Expressed sweet orange oil is a pale orange- yellow to dark orange or olive-orange, occasionally brownish-orange colored mobile liquid which has a sweet, light and fresh, fruity-aldehydic odor and flavor, distinctly reminiscent of the odor from a scratched sweet orange peel. Machine expressed oils are generally lighter in color, handpressed oils are usually darker (but not always). It is interesting to note that in the case of **Mandarin**** ****Oil,**** **the machine-pressed oils are darker than the hand-pressed. Guinea sweet orange oils may have a slightly olive-yellowish tint. Spanish oils can be very dark (ordinary Valencia oils), but are often the most powerful and rich in flavor. Expressed, sweet orange oil is used primarily in flavors, often in the shape of a concentrated oil, terpeneless or sesquiterpeneless oil (see these monographs). A certain amount of natural (non- concentrated) oil is a “must” to make an orange flavor true-to-nature. Too much of this oil may cause trouble such as: - deterioration and rancidity (off-flavor); - bleaching of the flavor due to the formation of peroxides from the monoterpenes; - unattractive “oil-ring”-formation in the bottleneck of carbonated beverages due to the poor solubility and low specific gravity of the monoterpenes. Orange flavors are among the most popular flavor types all over the world, and they are often superior in masking effect as compared to other fruit flavors. Soft drinks, sherbet ice, candy, pharmaceutical preparations, etc. are only a few of the countless outlets for sweet orange flavor. The oil furthermore enters as a minor constituent in numerous fruit flavors where it lends freshness and sweetness (peach, apricot, berry-flavors, etc.). The average use level could be suggested as 5.00 mg% up to 40.0 mg%. These figures apply to straight orange flavors where orange juice and acid are present, and the sugar content is not less than 10%. Concentrations as high as 40 mg% are found in orangeade and orange sodas, sherbets, fondants, etc. This concentration is beyond the threshold of solubility in aqueous media at the use temperature (usually between —4°C. and + 10°C.). Accordingly, it will be necessary to use solubilizers or emulsifiers in the liquid, aqueous products when the orange oil concentration exceeds 20 mg%. The **Minimum Perceptible **is 0.03 mg% to 0.06 mg%, with significant variations according to the type of oil. In perfumes, the application is a minor one. Old-fashioned eau-de-colognes, fougères,-chypres, aldehydic bases, fruity bases, etc. are among the most common areas of use. As an odor-masking agent, sweet orange oil is quite famous, but it has been substituted in many cases by “artificial” oils, i.e. mixtures of d-limonene, decyl aldehyde, nonyl aldehyde, etc. for masking certain ill- smelling industrial products. Expressed sweet orange oil is frequently adulterated with terpenes (d-limonene, isolated or “synthetic”) or with so-called “Citrus Oils”, a mixture of monoterpenes or distilled oils from the citrus fruit juice manufacturers. A flavor test is the best means of evaluating this very important material for flavors and perfumes.