Valencene

Aroma and sensory profile

Valencene is the part of orange peel that is not limonene. Fragrance references type it citrus with medium strength and describe it at 10 percent as sweet, fresh citrus, grapefruit, woody, orange, dry, green, and oily; its flavor is orange, citrus, fruity, juicy, citrus peel, and woody [1]. Where limonene is bright and thin, valencene is rounder, juicier, and a little woody. It is far less volatile than limonene, so it is the orange that remains once the sparkle has gone.

The molecule is a bicyclic sesquiterpene with three stereocenters, and it is chiral. The natural and commercial material is (+)-valencene; the CAS registry entry 4630-07-3 refers to that enantiomer, and JECFA specifications call for at least 94 percent purity with small amounts of bisabolene and farnesene [1]. No panel description of (−)-valencene was found, and it is not known to occur in nature, so no claim about how the two enantiomers differ in odor is made here. Its best-known relative is nootkatone, the grapefruit ketone, which is made industrially by oxidizing valencene [2].

Effects and research

No human trial of valencene was found. A 2023 review of valencene and nootkatone catalogued antimicrobial, insecticidal, antioxidant, and anti-inflammatory findings, noted that most studies are in animals and in vitro, and stated that both compounds are considered safe for consumption [2].

The anti-inflammatory data are from mice. Oral valencene at 10, 100, and 300 milligrams per kilogram inhibited paw edema, reduced interleukin-1 beta, tumor necrosis factor alpha, and myeloperoxidase in pleural and peritoneal lavage, and reduced chronic granuloma formation, with effects the authors compared to indomethacin and promethazine [3]. In a surgical osteoarthritis model, valencene reduced osteophytes, cartilage erosion, and subchondral bone damage, and in chondrocytes it lowered reactive oxygen species through the NRF2/HO-1 pathway [4].

The skin data are the most distinctive. Topical valencene reduced dinitrochlorobenzene-induced atopic dermatitis lesions in NC/Nga mice, lowered serum immunoglobulin E and interleukins 1 beta, 6, and 13, and restored the barrier proteins filaggrin and involucrin [5]. In melanoma cells, valencene from nutgrass rhizome inhibited the photoaging-related ion channels TRPV1 and ORAI1 and cut UVB-induced melanin by 83 percent at 15 micrograms per milliliter [6]. These are model results; none has been tested in people.

Natural sources

Valencene is a citrus sesquiterpene first and a sedge sesquiterpene second. Fragrance databases record it in orange, grapefruit, mandarin, lemon, lime, and blood orange oils, in clary sage, cedarwood, and pepper, mostly at trace levels and up to about 2.8 percent [1]. Valencia orange peel oil is the traditional source and the origin of the name, but citrus carries it at low concentration, which is why reviews describe valencene as traditionally obtained from citrus fruits that possess little of it and why most commercial valencene now comes from engineered yeast and bacteria expressing citrus valencene synthase [2][7]. The rhizome of Cyperus rotundus, nutgrass, is the main non-citrus botanical source and the one used in the skin studies above [6]. In cannabis valencene is a minor sesquiterpene, reported in a few sweet-citrus chemotypes at a small fraction of the caryophyllene level.

Boiling point and vaporization

No atmospheric-pressure boiling point for valencene appears in PubChem or in a primary paper found for this profile, so none is listed. PubChem compiles a single value from the Joint FAO/WHO Expert Committee on Food Additives, 123 °C at 11 mmHg [8], a vacuum-distillation figure that this site previously showed as if it were atmospheric. Fragrance references quote about 274 °C at atmospheric pressure [1], but that is an industry value rather than a measured one and is not adopted here. What can be said is that valencene is a sesquiterpene, well above every monoterpene on this site in boiling point and in the range of caryophyllene, so it persists in dried peel and in cooked citrus long after limonene has gone. No thermal degradation study was found.

Safety and regulation

Valencene is not listed by name in the FDA flavoring tables at 21 CFR 172.515 or 172.510; its flavor use rests on JECFA evaluation, whose specifications PubChem carries [8], and on FEMA GRAS status number 3443 [1]. The Research Institute for Fragrance Materials assessed valencene in 2018 and found no phototoxic hazard, negative genotoxicity, and acceptable margins for repeated-dose exposure, with a no-expected-sensitization-induction level set for skin [9]. No cancer classification applies.

Its skin record is clean. Under Europe's classification inventory the only hazard that clears the reporting threshold is aspiration, flagged in 98.5 percent of 1,685 notifications; no sensitization or irritation code reaches 10 percent [8]. That aspiration hazard is the one practical caution: like every liquid hydrocarbon terpene, neat valencene can be fatal if swallowed and drawn into the airways.

Industries and uses

Fragrance: valencene supplies a juicy, woody orange body in citrus and grapefruit accords and is the industrial feedstock for nootkatone [1][2]. Culinary: it holds FEMA GRAS and JECFA flavoring status and is used to rebuild fresh-orange character in juices, beverages, and confectionery [1][8]. Aromatherapy: sweet orange and grapefruit oils are its carriers; its low sensitization signal makes it one of the gentler citrus components on skin [8][9]. Cosmetics: the atopic dermatitis and photoaging results have drawn formulator interest in valencene and nutgrass extracts for barrier and brightening claims, all still preclinical [5][6].