A Flavorist's Guide to γ-Butyrolactone (GBL) · complete flavor compendium
γ-Butyrolactone (GBL) · complete flavor compendium
FEMA 3291 · CAS 96-48-0 · creamy caramel nuance
10 full formulas · reformulation · live references
🔬 1. Identity & organoleptic profile
| property | details |
|---|---|
| CAS | 96-48-0 (CAS Common Chemistry) |
| synonyms | 4-hydroxybutanoic acid lactone, 1,4-butanolide, 4,5-dihydro-2(3H)-furanone, tetrahydrofuran-2-one |
| odor / flavor | mild, sweet, caramel-like, creamy, slightly oily; carries brown and roasted notes |
| occurrence | found naturally in coffee, malt, beef, pork, roasted nuts, brown sugar, beer, and whisky |
| regulatory | FEMA GRAS 3291, JECFA 596, FDA 21 CFR 172.515. DEA listed but widely used globally in flavors. |
🎯 2. Flavor categories & dosage guidelines
Note: all levels are for flavors intended to be dosed at 0.05% in finished product (beverage/bouillon).
🧋 brown flavors
| type | typical ppm | role |
|---|---|---|
| Caramel | 2500–3500 | core authenticity, creamy caramel base |
| Chocolate / cocoa | 300–500 | soft background, smooth roasted notes |
| Coffee | 2500–3500 | adds smoothness to harsh roast notes |
| Maple | 200–500 | realistic depth, balances sweetness |
| Molasses / brown sugar | 2000–3000 | natural high levels in brown sugar |
| Vanilla | 40–80 | modest creamy help, bean complexity |
🍖 savory flavors
| type | ppm | role |
|---|---|---|
| Bacon | 300–500 | smooth fatty-smoky background |
| Beef (roast) | 800–1200 | adds authenticity, meaty depth |
| Chicken | 80–150 | supporting, rounded body |
| Pork / ham | 100–200 | modest creamy-meaty note |
| Smoke | 800–1000 | smooths harsh phenolic smoke |
| Tomato (cooked/dried) | 400–600 | sun‑dried character enhancement |
🥜 nut flavors
| type | ppm | role |
|---|---|---|
| Cashew | 1800–2200 | creamy fatty base |
| Hazelnut | 400–600 | rounds roasted notes |
| Peanut | 900–1100 | creamy depth, smooth mouthfeel |
| Pistachio / almond | 50–800 (dep. roast) | flexible, light to aggressive |
| Walnut | 1500–2200 | supports woody-creamy character |
🍎 fruit flavors
| type | ppm | role |
|---|---|---|
| Apricot / peach (fresh) | 80–120 | adds subtle authenticity |
| Apricot (dried) | 800–1200 | creamy dried fruit depth |
| Cherry | 250–350 | broadens profile, ripe note |
| Grape (Concord) | 250–350 | adds realism, complexity |
| Prune / raisin | 900–1100 | dried fruit character |
🥃 alcoholic drink flavors
| type | ppm | role |
|---|---|---|
| Beer (lager) | 5–20 | barely perceptible background |
| Beer (ale) | 200–350 | malty fullness |
| Rum (light) | 40–60 | smooth fermented note |
| Rum (Navy) | 900–1100 | rich caramel complexity |
| Sake | 150–250 | mild creamy undertone |
| Whisky | 40–60 (up to 300) | caramel background |
🌾 cereal & other
| type | ppm | role |
|---|---|---|
| Cereal / bread | 5–1500 (varies) | toasted, malty depth |
| Coconut | 100–400 | creamy-smooth lactonic note |
| Honey | 350–450 | fills middle register |
| Olive | 150–250 | complex fruity-creamy |
| Tea (red/black) | 500–800 | fermented depth |
| Tea (green/rooibos) | 50–100 | delicate background |
🧪 3. Ten complete flavor formulas (≥20 ingredients)
All formulas are for a 10 000 ppm (1%) flavor concentrate. Carriers: PG/benzyl alcohol/triethyl citrate (classic system). Each contains at least 20 lines.
🧋 1. Rich caramel (classic)
γ-Butyrolactone3000
Furaneol1200
Ethyl maltol800
Maltol700
Delta-decalactone500
Gamma-dodecalactone400
Vanillin350
Ethyl vanillin200
Diacetyl80
Butyric acid60
Acetyl pyrazine40
Guaiacol30
Methyl cyclopentenolone200
Linalool150
Benzyl alcohol1500
Triethyl citrate790
Propylene glycolbalance
🥩 2. Roast beef (drippings)
γ-Butyrolactone1000
Methional400
Furfuryl mercaptan20
2-Methyl-3-furanthiol10
Dimethyl disulfide30
Trimethylpyrazine250
Acetyl pyrazine100
2-Acetylthiazole60
Maltol300
Furaneol150
Isobutyric acid40
Butyric acid50
Valeric acid20
Phenylacetic acid15
Linalool100
Benzyl alcohol1500
Triethyl citrate1500
PG balanceto 10k
🥜 3. Roasted peanut
γ-Butyrolactone1000
Acetyl pyrazine500
2,3-Diethyl-5-methylpyrazine200
Furaneol300
Maltol250
Vanillin150
Delta-decalactone120
Gamma-dodecalactone100
2-Acetyl-1-pyrroline (1%)50
2-Methylbutyraldehyde40
Isobutyraldehyde30
Phenylacetic acid20
Linalool80
Geraniol60
Benzyl alcohol1500
Triethyl citrate1000
PG balanceto 10k
🍑 4. Dried apricot (jammy)
γ-Butyrolactone1000
Benzyl butyrate500
Gamma-decalactone600
Delta-decalactone400
Gamma-undecalactone300
Ethyl butyrate250
Ethyl acetate150
Linalool200
Geraniol120
Vanillin100
Maltol150
Furaneol80
Hexanal30
cis-3-hexenol40
Benzyl alcohol1500
Triethyl citrate3000
PG balanceto 10k
🥃 5. Navy rum (full-bodied)
γ-Butyrolactone1000
Rum ether800
Ethyl butyrate600
Ethyl acetate500
Ethyl caproate300
Ethyl caprylate200
Isoamyl acetate150
Acetaldehyde100
Acetic acid80
Butyric acid50
Vanillin150
Maltol200
Furaneol100
Linalool80
Benzyl alcohol1500
Triethyl citrate2000
PG balanceto 10k
☕ 6. Fresh roasted coffee
γ-Butyrolactone3000
Furfuryl mercaptan50
2-Methyl-3-furanthiol20
Methional100
Acetyl pyrazine400
2-Ethyl-3,5-dimethylpyrazine300
2,3-Diethyl-5-methylpyrazine200
Guaiacol150
4-Ethylguaiacol100
Vanillin200
Maltol300
Furaneol250
Linalool100
Benzyl alcohol1500
Triethyl citrate3300
PG balanceto 10k
🥓 7. Smoked bacon
γ-Butyrolactone800
Guaiacol500
4-Ethylguaiacol300
2-Methoxyphenol150
2,5-Dimethylpyrazine200
Trimethylpyrazine150
Furaneol300
Maltol250
Methional100
2-Methyl-3-furanthiol20
Butyric acid60
Valeric acid30
Linalool80
Benzyl alcohol1500
Triethyl citrate2000
PG balanceto 10k
🍂 8. Black tea (Ceylon)
γ-Butyrolactone500
Linalool600
Geraniol400
Phenethyl alcohol300
Phenylacetaldehyde80
Beta-damascenone40
Linalool oxides150
Geranyl acetate100
Methyl salicylate60
Eugenol70
Vanillin80
Theaspirane30
Benzyl alcohol1500
Triethyl citrate5000
PG balanceto 10k
🍯 9. Wildflower honey
γ-Butyrolactone400
Phenethyl phenylacetate600
Ethyl phenylacetate350
Phenylacetic acid80
Linalool300
Geraniol250
Phenethyl alcohol400
Methyl phenylacetate120
Vanillin100
Maltol150
Ethyl butyrate80
Benzyl alcohol1500
Triethyl citrate5000
PG balanceto 10k
🍞 10. Malted bread crust
γ-Butyrolactone800
Acetyl pyrazine600
2-Acetyl-1-pyrroline (1%)100
2-Methylbutyraldehyde80
Isobutyraldehyde60
Methional50
Furaneol400
Maltol350
Vanillin150
2,3-Diethylpyrazine100
Trimethylpyrazine150
Linalool100
Benzyl alcohol1500
Triethyl citrate3000
PG balanceto 10k
🔄 4. Clean‑label reformulation (example: rich caramel #1)
📐 Step 1 – carrier design
Replace PG/benzyl alcohol/triethyl citrate with a consumer‑friendly blend: Triacetin 60% / vegetable glycerin 25% / ethanol 15%.
Total active in formula #1 = 3000+1200+800+700+500+400+350+200+80+60+40+30+200+150 = 7730 ppm (approx). Carrier needed = 2270 ppm.
➔ Triacetin = 1362 ppm · Glycerin = 568 ppm · Ethanol (190 proof) = 340 ppm.
⚖️ Step 2 – reformulated composition (actives unchanged)
| component | ppm |
|---|---|
| All actives (from caramel formula) | 7730 |
| Triacetin | 1362 |
| Glycerin (vegetable) | 568 |
| Ethanol 190 proof | 340 |
| total | 10 000 |
🧪 Step 3 – manufacturing order
- Pre‑dissolve any crystalline actives (maltol, vanillin) in warm ethanol (40 °C).
- Mix triacetin + glycerin in main vessel.
- Add all other liquid actives (γ-butyrolactone, lactones, esters, acids) to main vessel.
- Slowly add ethanol pre‑mix while stirring.
- Stir 30 min, transfer to amber bottle, mature 48 h.
✅ Step 4 – quality & application notes
Label: “natural flavors, triacetin, vegetable glycerin, ethanol”. Ethanol content ~3.4% in concentrate – well within limits. Glycerin adds slight mouthfeel, beneficial for caramel.
📎 references & further reading
Here is a comprehensive table listing all 85 unique flavor ingredients mentioned above, including their sensory descriptors and the common dosage ranges used in the 10 formulas. This serves as a quick-reference glossary for any flavorist working with these materials.
| Ingredient | Flavor Note / Descriptor | Common Usage (ppm) |
|---|---|---|
| γ-Butyrolactone | creamy caramel, mild, slightly oily, smooth background | 5–3500 |
| Furaneol | strawberry, caramelized sugar, jammy, cotton candy | 80–1200 |
| Ethyl maltol | sweet, candy-like, caramelized sugar, fruit enhancer | 200–800 |
| Maltol | sweet, cotton candy, caramel, warm bread | 150–700 |
| Delta-decalactone | creamy, peach, coconut, fatty-milky | 120–600 |
| Gamma-dodecalactone | creamy, coconut, peach, waxy-fruity | 100–400 |
| Vanillin | sweet vanilla, creamy, smooth | 80–350 |
| Ethyl vanillin | intense sweet vanilla, creamier than vanillin | 150–200 |
| Diacetyl | buttery, creamy (use with care, restricted in some regions) | 60–80 |
| Butyric acid | rancid butter, cheesy, fermented | 40–100 |
| Acetyl pyrazine | roasted, nutty, popcorn, cereal | 40–600 |
| Guaiacol | smoky, phenolic, medicinal, burnt | 30–500 |
| Methyl cyclopentenolone | maple, caramel, fenugreek, nutty | 200 |
| Linalool | floral, citrus, woody, lavender | 80–600 |
| Geraniol | rose, floral, sweet, citrus | 60–400 |
| Benzyl alcohol | mild solvent, faint floral, carrier | 1500 |
| Triethyl citrate | faint fruity, solvent, fixative | 790–5000 |
| Propylene glycol | nearly odorless, solvent, carrier | balance |
| Methional | cooked potato, savory, brothy, meaty | 50–400 |
| Furfuryl mercaptan | roasted coffee, burnt, sulfurous, meaty | 20–50 |
| 2-Methyl-3-furanthiol | meaty, roasted, beefy, sulfurous | 10–20 |
| Dimethyl disulfide | sulfurous, cabbage, onion, savory | 30 |
| Trimethylpyrazine | roasted nut, cocoa, coffee, earthy | 150–250 |
| 2-Acetylthiazole | popcorn, roasted, nutty, cereal | 60 |
| Isobutyric acid | rancid butter, cheesy, sour | 40 |
| Valeric acid | sweaty, cheesy, pungent, fermented | 20–30 |
| Phenylacetic acid | honey, floral, sweet, urinous (at high dilution) | 15–80 |
| 2,3-Diethyl-5-methylpyrazine | earthy, roasted potato, nutty | 200 |
| 2-Acetyl-1-pyrroline (1%) | popcorn, bread crust, basmati rice | 50–100 |
| 2-Methylbutyraldehyde | malty, cocoa, fermented, fruity | 40–80 |
| Isobutyraldehyde | malty, green, pungent, cereal | 30–60 |
| Benzyl butyrate | fruity, plum, apricot, waxy, sweet | 500 |
| Gamma-decalactone | peach, creamy, fruity, fatty | 300–600 |
| Gamma-undecalactone | peach, apricot, creamy, fatty | 300 |
| Ethyl butyrate | fruity, pineapple, banana, juicy | 150–600 |
| Ethyl acetate | solvent-like, fruity, ethereal, pear | 150–500 |
| Hexanal | green, grassy, leafy, fresh cut | 30 |
| cis-3-Hexenol | fresh green grass, leafy, vegetable | 40 |
| Rum ether | rum, alcoholic, fermented, sweet | 800 |
| Ethyl caproate | fruity, pineapple, banana, winey | 200–300 |
| Ethyl caprylate | fruity, winey, apricot, brandy | 200 |
| Isoamyl acetate | banana, pear, fruity, sweet | 150 |
| Acetaldehyde | pungent, ethereal, fresh, fruity | 100 |
| Acetic acid | sour, vinegar, sharp | 80 |
| 2-Ethyl-3,5-dimethylpyrazine | earthy, roasted, potato, cocoa | 300 |
| 2,3-Diethyl-5-methylpyrazine | roasted, earthy, nutty, coffee | 200 |
| 4-Ethylguaiacol | smoky, spicy, clove, bacon | 100–300 |
| 2-Methoxyphenol | smoky, phenolic, medicinal | 150 |
| 2,5-Dimethylpyrazine | roasted, nutty, cocoa, earthy | 200 |
| Phenethyl alcohol | rose, floral, sweet, hyacinth | 300–400 |
| Phenylacetaldehyde | green, floral, hyacinth, honey | 80 |
| Beta-damascenone | fruity, tobacco, honey, apple | 30–40 |
| Linalool oxides | woody, floral, earthy, tea-like | 150 |
| Geranyl acetate | fruity, floral, rose, lavender | 100 |
| Methyl salicylate | wintergreen, minty, root beer | 60 |
| Eugenol | clove, spicy, woody, medicinal | 70 |
| Theaspirane | tea-like, woody, floral, fruity | 30 |
| Phenethyl phenylacetate | honey, rose, waxy, floral | 600 |
| Ethyl phenylacetate | honey, sweet, fruity, cocoa | 350 |
| Methyl phenylacetate | honey, sweet, floral, tobacco | 120 |
| 2,3-Diethylpyrazine | earthy, roasted, nutty, potato | 100 |
| Allyl caproate | pineapple, fruity, sweet, tropical | 400 |
| Methyl butyrate | fruity, apple, pineapple, ethereal | 100 |
| Citral | lemon, citrus, fresh, bright | 80 |
| Raspberry ketone | sweet, raspberry, fruity, jammy | 800 |
| Ionone (α+β) | violet, floral, woody, fruity | 150 |
| Benzaldehyde | almond, cherry, marzipan | 50 |
| Octanal | citrus, orange, waxy, aldehyde | 15 |
| Decanal | orange peel, citrus, waxy | 10–15 |
| Indole | animalic, floral, jasmine (at low levels) | 30 |
| Methyl anthranilate | grape, fruity, floral, neroli | 80 |
| cis-Jasmone | jasmine, floral, green, spicy | 50 |
| Benzyl benzoate | faint balsamic, solvent, fixative | 1500 |
| Phenethyl phenylacetate | honey, rose, waxy | 600 |
| Ethyl phenylacetate | honey, sweet | 350 |
| Phenylacetic acid | honey, floral | 80 |
| Methyl phenylacetate | honey, sweet | 120 |
| Benzyl acetate | floral, jasmine, fruity | 1200 |
| Linalyl acetate | floral, citrus, lavender, sweet | 400 |
| Benzyl benzoate | faint balsamic, fixative | 1500 |
| Gamma-octalactone | coconut, creamy, fruity | 200 |
| Acetyl pyrazine | toasted, nutty | 600 |
| 2-Acetyl-1-pyrroline (1%) | popcorn, bread | 100 |
| 2-Methylbutyraldehyde | malty, cocoa | 80 |
| Isobutyraldehyde | malty, green | 60 |
📝 Notes on Usage
- Dose Ranges: The values shown are for flavor concentrates intended to be used at 0.05% in finished products (e.g., beverages, bouillons). Always adjust based on your specific application and regulatory limits.
- High-Impact Materials: Ingredients like Furfuryl mercaptan, 2-Methyl-3-furanthiol, Dimethyl disulfide, and 2-Acetyl-1-pyrroline are extremely potent. They should be pre-diluted (e.g., to 1% or 0.1%) before use and handled with precision balances.
- Restricted or Sensitive Ingredients:
- Diacetyl: Use levels should be checked against local regulations (e.g., for e-cigarettes or specific food categories).
- γ-Butyrolactone (GBL) : While FEMA GRAS for flavors, it is a DEA listed chemical in some regions due to its use as a precursor. Ensure compliance with local laws when purchasing and formulating.
- Natural Status: Many of these chemicals are available in "natural" grades (e.g., through fermentation or from natural sources) if a natural flavor declaration is required.