Part 8 (para-menth-1-en-8-thiol myrcene valencene 1,8-cineole neryl oxide linalool oxide 2-phenyl ethanol benzaldehyde 4(4-hydroxy phenyl)-2-butanone 2-phenyl acetic acid)

These are among the 128 synthetic flavor compounds that John Wright, in his book Flavor Creation, suggests every flavorist should know and work with.

Below is the fully revised content with CAS numbers, standardized formatting, clarified regulatory notes, expanded technical details, and safety/handling information for each compound.

Important Synthetic Flavor Compounds – Part 8 (Enhanced Edition)

para‑Menth‑1‑ene‑8‑thiol (Grapefruit Mercaptan)

• CAS Number: 71159-90-5
• FEMA Number: 3700
• Regulatory Status: FEMA GRAS. Verify current status on the latest FEMA GRAS lists; due to its potency, it is subject to ongoing review.
• Flavor Note(s): Intensely citrus, grapefruit, juicy, sulfury, tropical. The primary character‑impact compound of grapefruit.
• Odor Threshold: ≈ 0.0001 ppb in water (extremely low).
• Compounds That Render Similar Flavor Note: 4‑Mentha‑8‑thiol‑3‑one (catty, black currant), other citrus thiols, grapefruit oil.
• Compounds Often Used Together With: Citrus terpenes (nootkatone, valencene, d‑limonene) and aldehydes (decanal, octanal).
• All Potential Applications: Grapefruit, orange, other citrus flavors for beverages, candies, functional products.
• General Usage Levels: Finished product: 0.05–2 ppb. Flavor concentrate: 0.0001–0.001% (1–10 ppm). Always handle as a highly diluted solution (0.01–0.1%) in triacetin, ethanol, or benzyl alcohol.
• Safety & Handling: Extremely potent sulfur compound; causes rapid olfactory fatigue. Store in a cool, dark place under inert gas (nitrogen) in tightly sealed containers. Flash point: 195 °F (91 °C) TCC. Use fume hood and PTFE/glass containers; avoid soft plastics. Shelf life: 12–18 months.

Myrcene

• CAS Number: 123-35-3
• FEMA Number: 2762
• Regulatory Status: FEMA GRAS for naturally occurring myrcene. Synthetic myrcene is not permitted for addition to food in the United States after October 9, 2020. JECFA No. 1327.
• Flavor Note(s): Balsamic, fruity, geranium, herb, must; sweet, terpenic aroma.
• Odor Threshold: ≈ 15–30 ppb in water.
• Compounds That Render Similar Flavor Note: Ocimene (more citrusy, lighter), limonene, pinene.
• Compounds Often Used Together With: Other terpenes in citrus, spice, fruit flavor complexes.
• All Potential Applications: Citrus, fruit, spice flavors for beverages, candies, baked goods; fragrance uses. (Synthetic version restricted in US food.)
• General Usage Levels: Finished product: 2–30 ppm (for naturally derived or pre‑restriction stocks). Flavor concentrate: 0.02–0.3% (200–3000 ppm).
• Safety & Handling: Combustible liquid. Flash point: 103 °F (39 °C). Store in a cool, dry place, protected from light and heat. Use proper grounding when transferring. Shelf life: 24 months.

Valencene

• CAS Number: 4630-07-3
• FEMA Number: 3443
• Regulatory Status: FEMA GRAS. International note: In China, regulated as a synthetic food flavor with specific food categories and maximum content limits (NHC).
• Flavor Note(s): Citrus, orange, fresh, woody. Key character‑impact compound in orange juice.
• Odor Threshold: ≈ 10–30 ppb in water.
• Compounds That Render Similar Flavor Note: Nootkatone (grapefruit, more ketonic), d‑limonene (lighter).
• Compounds Often Used Together With: Nootkatone, d‑limonene, other citrus terpenes and aldehydes.
• All Potential Applications: Orange, tangerine, grapefruit, other citrus flavors for beverages, candies, baked goods.
• General Usage Levels: Finished product: 5–50 ppm. Flavor concentrate: 0.05–0.5% (500–5000 ppm).
• Safety & Handling: Store in a cool, dry place, protected from light and air. Flash point: 212 °F (100 °C). Shelf life: 24 months.

1,8‑Cineole (Eucalyptol)

• CAS Number: 470-82-6
• FEMA Number: 2465
• Regulatory Status: FEMA GRAS.
• Flavor Note(s): Herbal, eucalyptus, camphor, minty, cooling. Fresh, clean, medicinal aroma.
• Odor Threshold: ≈ 1.3 ppb in water.
• Compounds That Render Similar Flavor Note: Camphor (more pungent), menthone (minty).
• Compounds Often Used Together With: Menthol, menthone, mint components; spice, herbal notes.
• All Potential Applications: Mint, eucalyptus, cough drops, candies, beverages, oral care, spice blends.
• General Usage Levels: Finished product: 5–100 ppm (cough drops up to 200–500 ppm). Flavor concentrate: 0.05–1.0% (500–10,000 ppm).
• Safety & Handling: Colorless to yellowish liquid. Flash point: 122 °F (50 °C) TCC. Practically insoluble in water. Store in a cool, dry place. Shelf life: 24 months.

Neryl Oxide

• CAS Number: 1786-08-9
• FEMA Number: 3661
• Regulatory Status: FEMA GRAS.
• Flavor Note(s): Green, vegetative, floral, leafy, waxy with herbal, minty depth.
• Odor Threshold: ≈ 10–50 ppb in water.
• Compounds That Render Similar Flavor Note: Nerol (floral, less green), linalool oxide (more musty‑camphor).
• Compounds Often Used Together With: Nerol, linalool, floral, green notes in citrus, berry, floral complexes.
• All Potential Applications: Citrus (neroli, petitgrain), berry, floral flavors for beverages, candies, baked goods.
• General Usage Levels: Finished product: 0.5–10 ppm. Flavor concentrate: 0.005–0.1% (50–1000 ppm).
• Safety & Handling: Colorless clear liquid. Flash point: 159 °F (70 °C) TCC. Store in a cool, dry place, protected from light. Shelf life: 24 months.

Linalool Oxide (Furanoid)

• CAS Number: 1365-19-1 (mixed isomers)
• FEMA Number: 3746
• Regulatory Status: FEMA GRAS.
• Flavor Note(s): Musty, camphor, fenchyl alcohol‑like, woody, earthy.
• Odor Threshold: ≈ 20–100 ppb in water.
• Compounds That Render Similar Flavor Note: Linalool (floral, less musty); pyranoid linalool oxide (CAS 14009-71-3).
• Compounds Often Used Together With: Linalool, other terpenes in lavender, bergamot, floral complexes.
• All Potential Applications: Lavender, bergamot, citrus, floral flavors for beverages, candies, baked goods.
• General Usage Levels: Finished product: 0.5–10 ppm. Flavor concentrate: 0.005–0.1% (50–1000 ppm).
• Safety & Handling: Pale yellow clear liquid. Flash point: 163 °F (73 °C) TCC. May cause skin sensitization; use gloves. Store in a cool, dry place, protected from light. Shelf life: 24 months.

2‑Phenyl Ethanol (Phenethyl Alcohol)

• CAS Number: 60-12-8
• FEMA Number: 2858
• Regulatory Status: FEMA GRAS. JECFA No. 987.
• Flavor Note(s): Honey, rose‑like, winy, floral, sweet. One of the most important rose aroma compounds.
• Odor Threshold: ≈ 100–1000 ppb in water (matrix‑dependent).
• Compounds That Render Similar Flavor Note: Geraniol (rose, more citrusy), citronellol (softer rose), phenethyl acetate (fruity‑rose).
• Compounds Often Used Together With: Geraniol, citronellol, phenethyl acetate for rose; also berry, stone fruit, wine.
• All Potential Applications: Rose, honey, strawberry, raspberry, apricot, peach, wine flavors for beverages, candies, baked goods, chewing gum.
• General Usage Levels: Finished product: 5–50 ppm. Flavor concentrate: 0.05–0.5% (500–5000 ppm).
• Safety & Handling: Colorless viscous liquid. Flash point: 216 °F (102 °C). Miscible with ethanol, propylene glycol. Store in a cool, dry place, protected from light. Shelf life: 24 months.

Benzaldehyde

• CAS Number: 100-52-7
• FEMA Number: 2127
• Regulatory Status: FEMA GRAS. JECFA No. 22.
• Flavor Note(s): Bitter almond, burnt sugar, cherry, malt, roasted pepper. Classic maraschino cherry/almond flavor.
• Odor Threshold: ≈ 100–350 ppb in water.
• Compounds That Render Similar Flavor Note: Benzaldehyde dimethyl acetal (more subtle almond), bitter almond oil. Nitrobenzene is toxic and never for flavor use.
• Compounds Often Used Together With: Vanillin, ethyl vanillin, fruit and nut components.
• All Potential Applications: Cherry, almond, maraschino cherry, walnut, pistachio, other nut/fruit flavors for beverages, candies, baked goods, chewing gum.
• General Usage Levels: Finished product: 5–500 ppm (cherry: 100–300 ppm; nut: 10–50 ppm). Flavor concentrate: 0.05–5% (500–50,000 ppm).
• Safety & Handling: Subject to oxidation (forms benzoic acid). Store in a cool, dark place under inert gas in tightly sealed containers. Flash point: 145 °F (63 °C). Shelf life: 12–24 months.

4‑(4‑Hydroxyphenyl)‑2‑Butanone (Raspberry Ketone)

• CAS Number: 5471-51-2
• FEMA Number: 2588
• Regulatory Status: FEMA GRAS.
• Flavor Note(s): Sweet, warm, fruity, raspberry. Primary character‑impact compound of raspberry.
• Odor Threshold: ≈ 10–30 ppb in water.
• Compounds That Render Similar Flavor Note: Raspberry juice, ionones (violet‑berry).
• Compounds Often Used Together With: Ionones, violet leaf absolute, cis‑3‑hexenol, ethyl acetate, ethyl butyrate.
• All Potential Applications: Raspberry, strawberry, berry flavors for beverages, candies, baked goods, dairy.
• General Usage Levels: Finished product: 5–50 ppm. Flavor concentrate: 0.05–0.5% (500–5000 ppm). Strawberry applications often use 2–15 ppm.
• Safety & Handling: White to slightly yellow solid. Melting range: 81–86 °C (178–187 °F). Flash point: 212 °F (100 °C). Dissolve in ethanol, PG, or triacetin. Store in a cool, dry place, protected from light and moisture. Shelf life: 24 months.

2‑Phenyl Acetic Acid (Phenylacetic Acid)

• CAS Number: 103-82-2
• FEMA Number: 2878
• Regulatory Status: FEMA GRAS.
• Flavor Note(s): Sweet, floral, honey, rose, chocolate, tobacco, powdery with animal nuances.
• Odor Threshold: ≈ 50–200 ppb in water.
• Compounds That Render Similar Flavor Note: Phenylacetaldehyde (more green, hyacinth‑like), methyl phenylacetate (honey, less animalic), phenethyl alcohol (rose).
• Compounds Often Used Together With: Phenethyl alcohol, benzaldehyde, other floral and sweet notes.
• All Potential Applications: Honey, chocolate, cocoa, tobacco, rose, floral flavors for beverages, candies, baked goods, tobacco products.
• General Usage Levels: Finished product: 1–20 ppm (chocolate/honey: 10–20 ppm; floral: 1–5 ppm). Flavor concentrate: 0.01–0.2% (100–2000 ppm).
• Safety & Handling: White crystalline powder. Melting point: 76–78 °C (169–172 °F). Slightly soluble in cold water. Flash point: 212 °F (100 °C) TCC. May cause skin/respiratory irritation; use adequate ventilation and PPE. Store in a cool, dry place, protected from heat and light. Shelf life: 24 months.

Below is the original version

para-Menth-1-ene-8-thiol (Grapefruit Mercaptan)

• FEMA Number: FEMA No. 3700, Consult the latest FEMA GRAS lists for the most current status.
• Flavor Note(s): Intensely citrus, grapefruit, juicy, sulfury, tropical. It is the primary character-impact compound of grapefruit, providing the distinct "grapefruit" aroma with its characteristic sulfurous, juicy, and slightly tropical nuance .
• Compounds That Render Similar Flavor Note: 4-Mentha-8-thiol-3-one (catty, black currant, also grapefruit-like), other thiols with citrus character, grapefruit oil.
• Compounds Often Used Together With: Used with other citrus terpenes (nootkatone, valencene, d-limonene) and aldehydes (decanal, octanal) to build authentic grapefruit and other citrus profiles.
• All Potential Applications: Grapefruit, orange, and other citrus flavors for beverages, candies, and functional products.
• General Usage Levels: Extremely potent. Used at extremely low levels, typically in the parts per billion (ppb) range in the finished product.
• Important Considerations for Flavorists: This compound is an extremely potent sulfur compound with an intense odor that can cause olfactory fatigue. It must be handled with extreme care, almost always as a diluted solution. It is sensitive to oxidation and should be stored in a cool, dark place in tightly sealed containers under inert gas . Flash point is approximately 195°F TCC .

Myrcene

• FEMA Number: 2762
• Flavor Note(s): Balsamic, fruity, geranium, herb, must . It has a pleasant, sweet, and terpenic aroma.
• Compounds That Render Similar Flavor Note: Ocimene (more citrusy, lighter), other monoterpene hydrocarbons like limonene and pinene.
• Compounds Often Used Together With: Used with other terpenes in citrus, spice, and fruit flavor complexes. It is a common component of many essential oils (hop, lemongrass, bay) and is used to add freshness and lift.
• All Potential Applications: Citrus, fruit, and spice flavors for beverages, candies, and baked goods. Also used in fragrance applications.
• General Usage Levels: Used at low to moderate levels. In finished products, typical usage ranges from 2 to 30 ppm.
• Important Considerations for Flavorists: It is important to note that the synthetic version of myrcene is not permitted for addition to food in the United States after October 9, 2020 . JECFA number 1327 . Store in a cool, dry place in tightly sealed containers, protected from light and heat. FEMA GRAS status is subject to this regulatory restriction.

Valencene

• FEMA Number: 3443
• Flavor Note(s): Citrus, orange, fresh, woody. It is a key character-impact compound in orange juice and provides a sweet, fresh, and juicy orange aroma.
• Compounds That Render Similar Flavor Note: Nootkatone (grapefruit, more ketonic), d-limonene (orange, but lighter), other sesquiterpene hydrocarbons.
• Compounds Often Used Together With: Used with nootkatone, d-limonene, and other citrus terpenes and aldehydes to build authentic orange and other citrus profiles.
• All Potential Applications: Orange, tangerine, grapefruit, and other citrus flavors for beverages, candies, and baked goods.
• General Usage Levels: Used at low to moderate levels. In finished products, typical usage ranges from 5 to 50 ppm.
• Important Considerations for Flavorists: In China, it is regulated as a synthetic food flavor and can only be used for that functional purpose, with specific applicable food categories and maximum content limits as per NHC regulations . Store in a cool, dry place. FEMA GRAS.

1,8-Cineole (Eucalyptol)

• FEMA Number: 2465
• Flavor Note(s): Herbal, eucalyptus, camphor, minty, cooling. It provides a fresh, clean, and medicinal aroma characteristic of eucalyptus oil .
• Compounds That Render Similar Flavor Note: Camphor (more pungent, less fresh), menthone (minty, less eucalyptus), other cineole derivatives.
• Compounds Often Used Together With: Used with menthol, menthone, and other mint components in mint flavors. Also used with spice and herbal notes in cough drop, candy, and oral care applications.
• All Potential Applications: Mint flavors, eucalyptus flavors, spice blends, cough drops, candies, beverages, and oral care products.
• General Usage Levels: Used at moderate levels. In finished products, typical usage ranges from 5 to 100 ppm, depending on the desired cooling and herbal intensity.
• Important Considerations for Flavorists: Colorless to yellowish liquid with a flash point of 122°F TCC. Practically insoluble in water . Store in a cool, dry place in tightly sealed containers. FEMA GRAS.

Neryl Oxide

• FEMA Number: 3661
• Flavor Note(s): Green, vegetative, floral, leafy, waxy with an herbal, minty depth. The taste is similarly green, vegetative, floral, leafy, and waxy with an herbal, minty depth .
• Compounds That Render Similar Flavor Note: Nerol (floral, less green), linalool oxide (more musty-camphor), other terpene oxides.
• Compounds Often Used Together With: Used with nerol, linalool, and other floral and green notes in citrus, berry, and floral flavor complexes.
• All Potential Applications: Citrus (especially neroli and petitgrain), berry, and floral flavors for beverages, candies, and baked goods.
• General Usage Levels: Used at low levels, typically in the range of 0.5 to 10 ppm in the finished product.
• Important Considerations for Flavorists: Colorless clear liquid with a flash point of 159°F TCC . Store in a cool, dry place in tightly sealed containers, protected from light. FEMA GRAS.

Linalool Oxide (Furanoid)

• FEMA Number: 3746
• Flavor Note(s): Musty, camphor, fenchyl alcohol-like, woody, earthy. It has a less floral and more woody-earthy character compared to linalool .
• Compounds That Render Similar Flavor Note: Linalool (floral, less musty), linalool oxide (pyranoid form), other terpene oxides.
• Compounds Often Used Together With: Used with linalool and other terpenes in lavender, bergamot, and other citrus and floral flavor complexes to add depth and naturalness.
• All Potential Applications: Lavender, bergamot, other citrus, and floral flavors for beverages, candies, and baked goods.
• General Usage Levels: Used at low levels, typically in the range of 0.5 to 10 ppm in the finished product.
• Important Considerations for Flavorists: Pale yellow clear liquid with a flash point of 163°F TCC . Store in a cool, dry place in tightly sealed containers, protected from light. FEMA GRAS.

2-Phenyl Ethanol (Phenethyl Alcohol)

• FEMA Number: 2858
• Flavor Note(s): Honey, rose-like, winy, floral, sweet. It is one of the most important and characteristic rose aroma compounds .
• Compounds That Render Similar Flavor Note: Geraniol (rose, more citrusy), citronellol (softer rose), phenethyl acetate (fruity-rose).
• Compounds Often Used Together With: An essential component in rose, honey, and other floral flavors. Used with geraniol, citronellol, and phenethyl acetate to build complex rose profiles. Also used in berry, stone fruit, and wine flavors.
• All Potential Applications: Rose, honey, strawberry, raspberry, apricot, peach, and wine flavors for beverages, candies, baked goods, and chewing gum.
• General Usage Levels: Used at moderate levels. In finished products, typical usage ranges from 5 to 50 ppm.
• Important Considerations for Flavorists: JECFA number 987. Store in a cool, dry place in tightly sealed containers. FEMA GRAS.

Benzaldehyde

• FEMA Number: 2127
• Flavor Note(s): Bitter almond, burnt sugar, cherry, malt, roasted pepper . It is the classic maraschino cherry and almond flavor.
• Compounds That Render Similar Flavor Note: Benzaldehyde dimethyl acetal (more subtle almond), bitter almond oil, nitrobenzene (toxic, not for use).
• Compounds Often Used Together With: Used with vanillin, ethyl vanillin, and other fruit and nut components in cherry, almond, and other nut and fruit flavors.
• All Potential Applications: Cherry, almond, maraschino cherry, walnut, pistachio, and other nut and fruit flavors for beverages, candies, baked goods, and chewing gum.
• General Usage Levels: Used at moderate levels. In finished products, typical usage ranges from 5 to 500 ppm, depending on the application.
• Important Considerations for Flavorists: JECFA number 22 . It is subject to oxidation, especially to benzoic acid. It must be stored in a cool, dark place in tightly sealed containers, preferably under inert gas. FEMA GRAS.

4-(4-Hydroxyphenyl)-2-Butanone (Raspberry Ketone)

• FEMA Number: 2588
• Flavor Note(s): Sweet, warm, fruity, raspberry. It is the primary character-impact compound of raspberry, providing the distinct, sweet, and slightly jammy raspberry aroma .
• Compounds That Render Similar Flavor Note: Raspberry juice, other raspberry ketone derivatives, ionones (violet-berry).
• Compounds Often Used Together With: An essential component in raspberry flavors. Used with ionones, violet leaf absolute, cis-3-hexenol, and other fruity esters (ethyl acetate, ethyl butyrate) to build complex and realistic raspberry profiles.
• All Potential Applications: Raspberry, strawberry, and other berry flavors for beverages, candies, baked goods, and dairy products.
• General Usage Levels: Used at moderate levels. In finished products, typical usage ranges from 5 to 50 ppm.
• Important Considerations for Flavorists: White to slightly yellow solid with a melting range of 81-86°C . Flash point is 212°F. Store in a cool, dry place. FEMA GRAS.

2-Phenyl Acetic Acid (Phenylacetic Acid)

• FEMA Number: 2878
• Flavor Note(s): Sweet, floral, honey, rose, chocolate, tobacco, and powdery with animal nuances. The taste is sweet, floral, chocolate, honey, and tobacco .
• Compounds That Render Similar Flavor Note: Phenylacetaldehyde (more green, hyacinth-like), methyl phenylacetate (honey, less animalic), phenethyl alcohol (rose, less animalic).
• Compounds Often Used Together With: Used with phenethyl alcohol, benzaldehyde, and other floral and sweet notes in honey, chocolate, tobacco, and rose flavor complexes.
• All Potential Applications: Honey, chocolate, cocoa, tobacco, rose, and other floral and sweet flavors for beverages, candies, baked goods, and tobacco products.
• General Usage Levels: Used at low to moderate levels. In finished products, typical usage ranges from 1 to 20 ppm.
• Important Considerations for Flavorists: White crystalline powder with a melting point of 76-78°C . Slightly soluble in cold water. Flash point is 212°F TCC. Store in a cool, dry place in tightly sealed containers, protected from heat and light. Shelf life is 24 months or longer if stored properly . FEMA GRAS. d

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