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# Important Synthetic Flavor Compounds - Part 8 (Grapefruit Mercaptan, Myrcene, Valencene, 1,8-Cineole, Neryl oxide, Linalool oxide, 2-Phenyl ethanol, Benzaldehyde, Raspberry Ketone, Phenylacetic Acid)
- URL: https://www.flavorist.com/important-synthetic-flavor-compounds-part-8-grapefruit-mercaptan-myrcene-valencene-1-8-cineole-neryl-oxide-linalool-oxide-2-phenyl-ethanol-benzaldehyde-raspberry-ketone-phenylacetic-aci/
- Published: 2026-03-15T21:12:44.000Z
- Updated: 2026-03-28T13:20:16.000Z
- Author: Editor

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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