Important Synthetic Flavor Compounds - Part 12 (difurfuryl sulfide, maltol, ethyl maltol, indole, 2,3-dimethyl pyrazine, trimethyl pyrazine, tetramethyl pyrazine, 2-acetyl pyrazine, 2-methoxy-3-methyl pyrazine, 2-methoxy 3-ethyl pyrazine)

Editor

22 Mar 2026 • 6 min read

Part 12 (difurfuryl sulfide maltol ethyl maltol indole 2,3-dimethyl pyrazine trimethyl pyrazine tetramethyl pyrazine 2-acetyl pyrazine 2-methoxy-3-methyl pyrazine 2-methoxy 3-ethyl pyrazine)

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

Difurfuryl Sulfide

FEMA Number: 3238 .
Flavor Note(s): Powerful, earthy, mushroom, coffee, meaty, sulfury. The taste is earthy, mushroom, metallic, with bloody savory notes .
Compounds That Render Similar Flavor Note: Furfuryl mercaptan (coffee, meaty), 2-methyl-3-furanthiol (meaty), and other sulfur-containing furans.
Compounds Often Used Together With: Used with other sulfur compounds, furanones, and pyrazines in coffee, meat, and savory flavor complexes to build roasted and meaty profiles.
All Potential Applications: Coffee, meat (beef, chicken), savory flavors, and roasted notes.
General Usage Levels: Extremely potent. Used at very low levels, typically in the parts per billion (ppb) range in finished products.
Important Considerations for Flavorists: Appears as a yellow-brown to brown solid with a melting point of 29.00 to 32.00 °C. Flash point > 230.00 °F. TCC. LogP (o/w) is 2.51 . Store in a cool, dry place in tightly sealed containers. FEMA GRAS.

Maltol

FEMA Number: 2656 .
Flavor Note(s): Sweet, caramelic, cotton candy-like, fruity, with a jammy nuance. It enhances sweetness and provides a creamy mouthfeel.
Compounds That Render Similar Flavor Note: Ethyl maltol (more intense, sweeter), furaneol (strawberry, caramel), and other caramelic furanones.
Compounds Often Used Together With: Used extensively with ethyl maltol and vanillin in vanilla, chocolate, caramel, and fruit flavors. It synergizes with many sweet and fruity notes.
All Potential Applications: Vanilla, chocolate, caramel, butterscotch, strawberry, pineapple, and other fruit flavors for beverages, baked goods, confectionery, and dairy products.
General Usage Levels: Used at moderate levels. In finished products, typical usage ranges from 5 to 100 ppm, depending on the application.
Important Considerations for Flavorists: In China, it is regulated as a synthetic food flavor with specific applicable food categories and maximum content limits . Store in a cool, dry place. FEMA GRAS.

Ethyl Maltol

FEMA Number: 3487 .
Flavor Note(s): Sweet, sugary, caramelised, jammy, strawberry-like odour reminiscent of candyfloss (cotton candy). The flavor is sweet, burnt cotton sugar candy-like, with jammy, strawberry notes .
Compounds That Render Similar Flavor Note: Maltol (softer, less intense), furaneol (strawberry, caramel), and other caramelic compounds.
Compounds Often Used Together With: Used with vanillin (reinforces creamy sweetness), methyl anthranilate (adds grape-candy freshness), gamma-undecalactone (evokes peach or milky fruit), and delta-decalactone (deepens creamy and coconut-like effects) .
All Potential Applications: Vanilla, caramel, strawberry, pineapple, and other fruit flavors. Used extensively in confectionery, baked goods, soft drinks, and tobacco .
General Usage Levels: Highly diffusive and bloom-enhancing at low concentrations (0.05–0.3% in fragrance). Acts as a rounder and smoother in fruity-lactonic blends .
Important Considerations for Flavorists: Not restricted by IFRA (as of 51st Amendment). GRAS listed by FEMA. Stable in alcohol and oil bases with good thermal resistance . Store in a cool, dry place. FEMA GRAS.

Indole

FEMA Number: 2593 (Note: Not in search results, from general knowledge).
Flavor Note(s): Animal, fecal, mothball-like at high concentrations. At low dilutions, it becomes floral, jasmine-like, and sweet.
Compounds That Render Similar Flavor Note: Skatole (more fecal-intense), anthranilates (floral-grape), and other nitrogen-containing heterocycles.
Compounds Often Used Together With: Used with jasmine, neroli, and other white floral notes in floral flavors. Also used in cheese and animalic savory notes.
All Potential Applications: Jasmine, neroli, orange blossom, and other floral flavors. Used in some cheese and animalic flavor nuances.
General Usage Levels: Very potent. Used at extremely low levels, typically in the parts per billion (ppb) range in finished products. At higher concentrations, it becomes objectionable.
Important Considerations for Flavorists: Appears as white crystals with a melting point around 52°C. Can cause skin sensitization. Store in a cool, dark place in tightly sealed containers. FEMA GRAS.

2,3-Dimethyl Pyrazine

FEMA Number: 3271 .
Flavor Note(s): Nutty, nut skin, cocoa, peanut butter, coffee, walnut, caramellic, roasted, musty, powdery, potato .
Compounds That Render Similar Flavor Note: 2,5-Dimethylpyrazine (nutty, earthy), 2,6-Dimethylpyrazine (nutty, cocoa), and trimethylpyrazine (nutty, potato).
Compounds Often Used Together With: Used with other pyrazines, thiazoles, and furanones in nut, cocoa, coffee, and savory flavor complexes.
All Potential Applications: Nut flavors (peanut, walnut, filbert), cocoa, coffee, potato, corn chip, and baked good flavors .
General Usage Levels: High odor strength, recommend smelling in a 0.10% solution or less . In finished products, typical usage ranges from 0.5 to 10 ppm.
Important Considerations for Flavorists: Appears as a colorless to pale yellow clear liquid. Flash point 128.00 °F. TCC. Food Chemicals Codex listed . Store in a cool, dry place. FEMA GRAS.

Trimethyl Pyrazine (2,3,5-Trimethyl Pyrazine)

FEMA Number: 3244 .
Flavor Note(s): Nutty, musty, powdery cocoa, potato and musty odor. Taste is raw, musty, nutty, potato .
Compounds That Render Similar Flavor Note: Tetramethylpyrazine (nutty, cocoa, vanilla-like), 2,3-dimethylpyrazine (nutty, cocoa), and other alkylpyrazines.
Compounds Often Used Together With: Used with other pyrazines in cocoa, coffee, potato, and nut flavor complexes.
All Potential Applications: Cocoa, coffee, potato, peanut, and other nut and savory flavors.
General Usage Levels: Used at low to moderate levels. In finished products, typical usage ranges from 1 to 15 ppm.
Important Considerations for Flavorists: Appears as a colorless to pale yellow clear liquid. Flash point 130.00 °F. TCC . Store in a cool, dry place. FEMA GRAS.

Tetramethyl Pyrazine (2,3,5,6-Tetramethyl Pyrazine)

FEMA Number: 3237 .
Flavor Note(s): Nutty, musty and vanilla with dry, brown cocoa nuances. Taste is nutty, musty, cocoa, drying, peanut-like and raw coffee notes .
Compounds That Render Similar Flavor Note: Trimethylpyrazine (nutty, potato), 2,3-dimethylpyrazine (nutty, cocoa), and other alkylpyrazines with roasted notes.
Compounds Often Used Together With: Used with other pyrazines and furanones in cocoa, coffee, nut, and vanilla flavor complexes.
All Potential Applications: Cocoa, coffee, peanut, and other nut and brown flavors where a dry, roasted cocoa note is desired.
General Usage Levels: Used at low to moderate levels. In finished products, typical usage ranges from 0.5 to 10 ppm.
Important Considerations for Flavorists: Appears as white crystals with a melting point of 85.00 to 90.00 °C. Flash point > 200.00 °F. TCC . Store in a cool, dry place. FEMA GRAS.

2-Acetyl Pyrazine

FEMA Number: 3126 .
Flavor Note(s): Popcorn, nutty, corn chip, bread crust, chocolate, hazelnut, coffee, musty, roasted, potato odor. Flavor is roasted, nutty, bready, yeasty, popcorn, corn chip .
Compounds That Render Similar Flavor Note: 2-Acetyl-1-pyrroline (popcorn, but more intense), 2-acetylpyridine (popcorn, nutty), and other acetyl heterocycles.
Compounds Often Used Together With: Used with pyrazines, thiazoles, and furanones in popcorn, corn chip, bread, nut, and coffee flavor complexes.
All Potential Applications: Popcorn, corn chip, bread, roasted nut, coffee, and cocoa flavors for savory and baked goods applications .
General Usage Levels: Very high odor strength, recommend smelling in a 0.10% solution or less . Substantivity is 400 hour(s) at 10.00% in dipropylene glycol. In finished products, typical usage ranges from 0.1 to 5 ppm.
Important Considerations for Flavorists: Appears as white to pale yellow crystalline powder with a melting point of 76.00 to 78.00 °C. Flash point > 212.00 °F. TCC. Food Chemicals Codex listed . Store in a cool, dry place. FEMA GRAS.

2-Methoxy-3-Methyl Pyrazine

FEMA Number: 3249 .
Flavor Note(s): Potent earthy, nutty, and green bell pepper-like aroma. It has a strong, diffusive character with a low odor threshold, making it an impactful note even at low concentrations .
Compounds That Render Similar Flavor Note: 2-Methoxy-3-ethylpyrazine (earthy, potato), 2-isopropyl-3-methoxypyrazine (green pepper, earthy), and 2-isobutyl-3-methoxypyrazine (green pepper, bell pepper).
Compounds Often Used Together With: Used with other pyrazines and green notes in vegetable, nut, and earthy flavor complexes. It synergizes well with other pyrazines and green notes, enhancing complexity .
All Potential Applications: Vegetable flavors (bell pepper, pea, asparagus), nut flavors, and earthy profiles .
General Usage Levels: Extremely potent. Typical use levels in finished food products range from 0.01 to 0.1 ppm .
Important Considerations for Flavorists: Recognized as GRAS by FEMA. Approved in the EU under Regulation (EC) No 1334/2008 with FL No. 07.211. Formulators should be cautious of its potent aroma, as overuse can lead to an overpowering effect . The compound is stable under typical food processing conditions but may degrade under extreme heat or acidic environments. Store in a cool, dry place. FEMA GRAS.

2-Methoxy-3-Ethyl Pyrazine

FEMA Number: N/A (Note: FEMA number not found in search results; flavorists should consult current FEMA GRAS lists) .
Flavor Note(s): Earthy, raw potato, earthy, green pepper, bell pepper, nutty .
Compounds That Render Similar Flavor Note: 2-Methoxy-3-methylpyrazine (earthy, bell pepper), 2-isopropyl-3-methoxypyrazine (green pepper), and 2-isobutyl-3-methoxypyrazine (bell pepper).
Compounds Often Used Together With: Used with other methoxypyrazines and green notes in potato, vegetable, and wine flavor complexes.
All Potential Applications: Potato, vegetable (green pepper), and wine flavor nuances where an earthy, vegetative note is desired .
General Usage Levels: Extremely potent. Used at very low levels, typically in the parts per billion (ppb) range in finished products.
Important Considerations for Flavorists: Appears as a colorless clear liquid with a flash point of 156.00 °F. TCC. LogP (o/w) is 1.8 . Store in a cool, dry place in tightly sealed containers. Occurs naturally in grape, potato, and wine . FEMA GRAS status not confirmed from search results; verify before use.

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