Pinene orange

Crude turpentine is distilled to obtain refined products used in the fragrance and flavour industry. Only the unsaturated mono- and bicyclic terpenes are of interest for resin production. These are mainly a-pinene, p-pinene and dipentcne (D,L-limonene) (Fig. 17). D-Limonene is obtained by extraction of orange peel in citrus fruits. 

An alkene, sometimes caJled an olefin, is a hydrocarbon that contains a carbon-carbon double bond. Alkenes occur abundantly in nature. Ethylene, for instance, is a plant hormone that induces ripening in fruit, and o-pinene is the major component of turpentine. Life itself would be impossible without such alkenes as /3-carotene, a compound that contains 11 double bonds. An orange pigment responsible for the color of carrots, /3-carotene is a valuable dietary source of vitamin A and is thought to offer some protection against certain types of cancer. 

Several unsaturated cyclic hydrocarbons, having the general formula C]qHj5, occur in certain fragrant natural oils that are distilled from plant materials. These hydrocarbons are called terpenes and include pinene (in turpentine) and limonene (in lemon and orange oils). 

The two pinenes are obtained from Crude Sulfate Turpentine (CST), which is a side product of the sulfate cellulose process from pine trees. Limonene is present in orange and lemon peels [which provide different enantiomers/ )], and is a cheap by-product of the citrus industry. 

Mandarin peel oil volatiles contain many of the same volatiles as orange peel oil however, there are a few differences such as elevated levels of dimethyl an-thranilate and thymol. It has been reported [54] that the characteristic mandarin peel oil aroma was due to a combination of dimethyl anthranilate, thymol, a-terpinene and /1-pinene. 

Orange terpenes were emulsified in various carrier s and spray-dried. The spray-dried powders were aged for 3 days at 80 C in a draft oven. Beta-pinene is an oxidation product in orange terpenes which can be measured by GC. The beta-pinene level is proportional to the degree of oxidation of the orange terpenes. High levels of beta-pinene content in the spray-dried powders indicate poor oxidation resistance imparted to the encapsulated terpenes by the carrier. 

A Beckman Model 4 GC was equipped with a carbowax column, temperature 180 C (inlet). A microliter injection was made and the oxidized beta-pinene peak was measured. The retention time for the oxidized beta-pinene peak is 5.5 minutes. The encapsulated orange terpenes were first dissolved in water before injection. 

Another important aspect of encapsulation efficiency is the resistance to oxidation that the carrier imparts to the flavor oils. The oxidation resistance properties are critical to shelf-life stability of the encapsulated product. Oxidation properties can be measured organoleptically by a taste panel or by gas chromatograph of the recovered oil. Peaks related to oxidation products of orange terpenes obtained from GC analysis can be monitored as the powders are aged for three days at 80 C. The GC was used to measure beta-pinene, an oxidation product of orange terpenes. The results are reported in square inches. The greater the area for the beta-pinene peak, the poorer the oxidation resistance of carrier towards the orange terpenes. The data is presented in TABLE 5 ... 

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. 

Comparison of the taste threshold with estimated concentration in orange juice (where available) in Table I reveals that in all cases except octyl acetate and a-pinene, the concentration in orange juice exceeds the taste threshold in water for most values reported. Patton and Josephson (17) postulated that components present in a food at above threshold level make a positive contribution to the flavor, while those present at below threshold level make little or no contribution to flavor. This generalization is now considered an oversimplification, for synergistic effects among food constituents have been shown to decrease the threshold level of some compounds, and nonvolatile constituents are known to either increase or decrease the taste threshold of certain volatile and nonvolatile constituents. 

Limonene (3) a//3-Pinene (4, 5) Linalool (6) Menthol (7) Geraniol (8) Sweet orange (R) Pine wood ((+)-aa, (-)-ff) Ho (R), rosewood ( ) Japanese mint (-) Palmarosa Citronellol (9) Citronellal (10) 1,8-Cineole (1) Citral (11) Eugenol (2) Geranium (S) Eucalyptus (E citriodora, ), citronella (R) Eucalyptus (E globulus) Lemongrass, Litsea cubeba Glove... 

Defensive Compounds. Larvae of the weevil Oxyops vitiosa produce a shiny orange secretion that covers their integument and probably acts as deterrent against ants [420]. The composition of the secretion resembles the terpenoid pattern of the host foliage (Melaleuca quinquenervia) from where it is sequestered (concentration about twice that of the host foliage). It contains the sesquiterpene (+)-viridoflorol 230 (Scheme 25), the monoterpene hydrocarbons a-pinene 45, P-pinene 46, limonene 171, a-terpinene 231, and y-terpinene 232 as well as the oxygenated monoterpenesl,8-cineole 58, a-terpineol 233, and terpinen-4-ol 234. 

Pinane-type bicyclic monoterpenoids (Fig. 6) occur in the wood of several species of Pinus. The most abundant are a- and p-pinenes (F7 and F8, respectively). Ally lie hydrox-ylation products of pinenes, (+)-verbenol (F9), (+)-myrtenol (FIO), and (—)-pinocarveol (Fll) also occur in nature together with their products of oxidation (-f-)-verbenone (F12), (-h)-myrtenal (F13), and (-)-pinocarvone (F14). (-h)-Verbenol is a constituent of the oil of turpentine. Its regioisomers, (-h)-myrtenol and (—)-pinocarveol, occur in oils of orange Citrus sinensis, Rutaceae) and eucalyptus Eucalyptus globulus, Myrtaceae), respectively. 

CIC Acetaldehyde, although weak in smell and taste, is an important contributor to juiciness and freshness. Ethyl butyrate and (E)-2-hexenol add the fruity, green note and alpha-pinene, octanal and decanal are responsible for the green peely, aldehydic orange note. 

Limonene is widespread in essential oils. The main source for (-i-)-limonene are citrus peel oils. From this source it is obtained in large quantities as a by-product of the orange juice production. Therefore nature-identical products (e.g. from pinene) are not of great importance. The 5 C-values of natural limonene from orange peel oil has been found to range from -26.1 to -28.5%o, and the reported 5 H-values are from -215 to -264%o, in agreement with results for other natural isoprenoids. 

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]. 

Camphene, a- Rosemary plant, P-Pinene, Cineole, and spruce needles Camphor, Bomeol, Bomyl Acetate, Humulene Cinnamaldehyde, Cinnamon Coumarin, C15H24 Isomers Limonene, a- Orange peel P-Pinene, C15H24 Limonene, Menthol, Chewing gum Isomenthone, Carvone, Menthone, C15H24 45 0.90 300... 

Limonene is obtained in large amounts as a byproduct in the production of orange juice (-)-limonene is isolated in relatively small quantities from essential oils. Racemic limonenes, which are commercially available under the name dipentene, are formed as byproducts in many acid-catalyzed isomerizations of a- and fl-pinene. Distillation of the so-called dipentene fraction yields limonenes in varying degrees of purity. 

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