Trimethyl Thiazole CAS 13623-11-5 Supplier & Manufacturer in China

While Subjected to Extrusion Above 150°C, Volatile Partitioning Dictates Carry-Through

When trimethyl thiazole is incorporated into extruded-expanded cereal matrices or structured vegetable protein streams, the primary processing conflict exists between flavour precursor retention and barrel zone devolatilisation. Barrel profiles typically exceeding 155°C in the metering section induce a steep vapour pressure increase for the heterocycle (calculated Antoine-derived vapour pressure at 155°C approximates 4.8 kPa), leading to annular vapour entrainment toward the vent port. Production-scale twin-screw extruders with L/D ratios of 36:1 to 44:1 show observed carry-through rates no higher than 35–40% when the aroma chemical is pre-blended with dry cereal fines alone. To shift the partitioning coefficient toward the molten starch-protein continuum, a lipid-anchoring pre-dispersion step proves mandatory. The compound is first solubilised at 15–20% (w/w) in refined palm kernel stearin or high-oleic sunflower oil held at 65°C, then dosed via liquid injection port downstream of the reverse-screw element where melt temperature is maintained at 120±3°C. This repositions the carry-through into the 62–70% range as determined by GC-MS headspace yield on collected pellets.

Formulation criticality extends to the matrix's reducing sugar payload. Fructose-glucose syrups added above 6% on dry solids promote Schiff base sequestration of the thiazole's ring-bearing methyl substituents during barrel residence, yielding trace oxazolidine by-products identifiable on polar column retention time shifts. Blenders therefore quantify free glucose using Luff-Schoorl titration per ISO 5377:1981 prior to flavour dosage. The oil-anchored trimethyl thiazole is metered to deliver a final loading of 1.8–2.5 ppm in the breakfast cereal or texturised meat analogue on a ready-to-eat basis, falling under the FEMA 3325 usage ceiling for grain products. EU compliance anchors to Regulation (EC) 1334/2008, Annex I, Part A, with the registered flavouring substance code FL 15.022. Shelf-life sensory panels at 38°C/85% RH over 12 weeks confirm headspace fade under bare paperboard packaging; the limitation is overcome via aluminised PET laminates directing WVTR below 0.05 g/m²·day. Industrial end-products include protein crisps, filled pillow cereals, and meatless nugget breading.

Where carbonated soft drinks rely on trimethyl thiazole for cocoa-nutty top notes in cola-type emulsions or tropical fruit blends incorporating creamy back-notes, the dominant technical hurdle shifts from thermal lability to acid-catalysed ring rearrangement in illuminated storage. The ingredient is pre-diluted to a 0.1% (w/w) stock solution in propane-1,2-diol (USP/EP grade) with dissolved oxygen purged to below 0.5 mg/L via nitrogen sparge. Dosage in the syrup phase is regulated at 0.8–1.2 ppm of the final beverage, aligning with FEMA 3325 average use levels for non-alcoholic beverages. pH drifts observed in citric-phosphoric acid systems below 2.8 prompt disulphide-like off-odour formation after 4 weeks at 30°C under fluorescent retail lighting simulating ISO 105-B02:2014 cycle conditions. To counteract this, emulsion formulators introduce mixed tocopherols (E306) at 50 ppm relative to oil phase and mandate storage at ≤ 8°C for the neat flavour emulsion before dosing. The finished beverage undergoes short-time pasteurisation at 72°C/15 s on tubular exchangers prior to counter-pressure filling into monolayer PET preforms coated with active oxygen-scavenging barrier layers. Market end-products span low-calorie cola alternatives, chocolate-mint enhanced sparkling water, and clarified functional drinks aimed at protein-backnote simulation without dairy.

Does Low-pH Baked Snack Processing Degrade the Thiazole Ring Before the Drying Phase Completes?

In cracker and hard-biscuit manufacturing where dough pH is deliberately lowered to 4.2–4.6 using lactic acid or glucono-delta-lactone for gluten management, trimethyl thiazole added before the laminating reduction roller stage undergoes acid-mediated electrophilic substitution risk at the 5-position methyl group. Dough temperatures during multi-zone tunnel baking rise from 28°C to 210°C over a 4.5–6.5 minute residence, and protonation of the thiazole nitrogen at the acidic wedge point adjacent to the oven’s first zone (product surface temperature 95–100°C) weakens methyl substituent C-H bonds measurable via deuterium exchange experiments. Large-scale wafer plants using direct-gas-fired convection ovens have logged 12–18% net compound destruction when the flavourant is dry-blended into the dough, determined by stable isotopic dilution assay (SIDA) on finished biscuits. To arrest this pathway, the flavour is instead post-sprayed onto the hot biscuit immediately after the oiling stage at the exit of the oven where surface residual moisture content is 2.5–3.5% and product temperature has fallen to 135°C. The spray oil emulsion system contains trimethyl thiazole pre-emulsified at 0.05–0.08% in refined groundnut oil with lecithin (E322) at 0.2% as molecular bridging agent, achieving a surface adherence efficiency of 89–93% confirmed by surface-wash hexane extraction.

The baked snack sector observes EU flavourings legislation where trimethyl thiazole’s maximum permitted level in “fine bakery ware” is driven by the quantum satis principle under Regulation (EC) 1334/2008 but with adherence to the FEMA 3325 benchmark of 2.0 ppm aligning to JECFA No. 1060 structural classification. Shelf-stability challenge tests at 40°C/75% RH in metallised BOPP flow-wrap show ring-opening by-products develop predominantly at the seal-jaw contact points initiating micro-abrasion on the film’s aluminium layer, permitting trans-pack oxygen ingress. This informs a production rule: packs must achieve a seal integrity leak rate below standard 10 cm³/m²·day·atm as per ASTM D3985-17. End-product references: sesame sticks, baked pretzels with chocolate-seasoning blends, and gluten-free sorghum crackers where sulphurous-bread notes are suppressed.

Tobacco casing formulations integrate trimethyl thiazole to anchor roasted, cocoa-husk tonality in reconstituted sheet and expanded stem substrates. The compound is dissolved in a hot casing solution composed of inverted sugar syrup (65°Brix), liquorice extract solids at 2.5% w/w, and propylene glycol held at 75°C, applied via high-pressure atomisation nozzles (spray angle 80°, droplet size Dv90 45 µm) in a rotating drum humidifier immediately before the redrying stage. The application rate calibrates to deliver 5–15 µg of trimethyl thiazole per gram of cut filler, correlating to a smoke transfer rate measured under ISO 3308:2012 puffing regimen of 4–9 ng/cigarette. Because tobacco-specific regulation diverges substantially from food law, the substance falls under the overarching chemical inventory registration where REACH (EC) 1907/2006 full substance registration is mandatory for volumes exceeding 1 metric tonne/year per legal entity; additionally, the German Tobacco Ordinance (TabakerzV) Annex 1 listing must be confirmed. A process limitation emerges when the casing contains ammonia-licorice alkalising reactants — residual free ammonia above 0.05% in the substrate displaces the thiazole-acid equilibrium toward a Schiff-base adduct with tobacco-derived aldehydes, detectable as green-woody off-note. Compensation strategies involve raising casing pH buffer with phosphoric acid to 5.8 prior to flavour injection. The finished article spans Virginia-blend rolling tobacco, heat-not-burn stick tobacco plugs wrapped in low-ignition-propensity paper, and snus pasteurised pouch fill.

Carbonyl-Amine Pathway Steering in Reaction Mass Process Flavours

The synthesis of process flavourings conforming to EC 1334/2008 Article 9 category demands that trimethyl thiazole be treated as a pre-formed volatile contributor added to the reaction mass rather than generated in-situ, yet it critically modulates the carbonyl-amine cascade through competitive binding at the dicarbonyl intermediate stage. A reactor vessel (stainless steel AISI 316L jacketed with recirculating thermal oil) is charged with enzymatically hydrolysed vegetable protein (DH 28–32%), cysteine hydrochloride monohydrate at 1.2% w/w, xylose at 3.8% w/w, and thiamine hydrochloride at 0.6% w/w; the trimethyl thiazole is pre-mixed with the water phase to yield a final concentration of 8–12 ppm on total reaction mass. Heating proceeds rapidly to 110°C under 0.08 MPa back-pressure over 15 min and is held at that plateau for 90 min. The thiazole’s presence accelerates the formation of 2-methyl-3-furanthiol via Maillard rearrangement — confirmed through SPME-GC-TOFMS monitoring where the disulphide cross-coupling product becomes detectable at 42 min instead of the typical 58 min for a thiazole-free control. Reaction mass pH must be clamped at 5.0–5.4 with food-grade sodium hydroxide dosing, since pH excursions above 6.2 promote irreversible thiazole precipitation as a sulphur-bound melanoidin-coagulate.

Regulatory scrutiny for process flavourings is framed by JECFA 1060 and the FEMA 3325 GRAS affirmation, reinforced by EU positive list entry FL 15.022. Producers of savoury bouillons and meat analogue melt blends conduct batch-corrected dosing verification by diluting the process flavour 1:1000 in neutral oil and assaying trimethyl thiazole via GC-FID against an authentic standard (purity ≥98% by anhydrous assay per FCC 11 monograph). The commercial yield penalty is a 7–10% evaporative loss through the reflux condenser, captured by a chilled water trap operating at 4°C and recirculated once per cycle. End-product manifestations include hickory-smoked barbecue seasoning pastes, instant noodle seasoning oil sachets where flash point compliance above 120°C is maintained, and retorted wet pet food chunks targeting feline preference.

Crystallization Behaviour in Spray-Dried Fat-Encapsulated Systems

Confectionery and powder-beverage applications that demand protracted shelf-life without sensory fade pivot toward carbohydrate-glass encapsulation of trimethyl thiazole after high-shear emulsification into partially hydrogenated coconut oil (melting point 35–37°C). The primary technical justification lies in the compound’s vapour pressure suppressing effect when trapped in an amorphous sucrose-maltodextrin (DE 10–12) continuous phase. The oil phase contains the thiazole at 1.0% w/w and is emulsified with Quillaja saponin (E999) at 0.08% and octenyl succinic anhydride-modified starch (OSA-starch, E1450) at 4.5% of the aqueous carrier phase. High-pressure homogenisation at 65°C using a dual-stage homogeniser set to 25/5 MPa generates a droplet mean diameter (D[4,3]) of 0.9–1.1 µm; the feed is then atomised into a co-current spray dryer with inlet air at 190°C and exhaust at 90°C. Under these parameters, X-ray powder diffractograms confirm a non-crystalline halo devoid of sucrose recrystallisation peaks, and glass transition temperature (Tg) as measured by differential scanning calorimetry (ISO 11357-2:2020) remains at 48±2°C, safely above ambient storage conditions.

The stabilised powder is dry-blended into gelatine-free wine gum mixes (deposited into starch moguls at 72°Brix cooking mass), where it delivers a final residual level of 1.5 ppm methyl thiazole equivalent in the de-moulded, sugar-sanded pieces. Compliance is traceable to US FDA 21 CFR 172.515, which lists 2,4,5-trimethylthiazole as a synthetic flavour substance generally recognised as safe, and to the JECFA ADI “not specified” designation under the condition that consumption complies with good manufacturing practice. A documented failure mode occurs when confectionery slabs cool at rates below 2°C/min, permitting orthorhombic sucrose crystal growth that fractures the encapsulate matrix and releases thiazole to headspace within 14 days — detected as capping sheet exudate. Production orders specify forced-air cooling tunnels achieving 4.5°C/min on the deposition belt. Finished product classes encompass cocoa-dusted wafer praline centres, instant cappuccino foamer powder sticks, and chewable vitamin tablets where off-note masking without reactivity toward ascorbic acid is essential.

In some pet food coating systems targeting feline and canine palatability improvement, trimethyl thiazole is utilised not as a standalone character but as a synergist for pyrophosphate-activated liver hydrolysates. The aroma chemical is diluted to 0.02% in refined chicken fat heated to 50°C and applied via vacuum coater at 0.08 MPa negative pressure onto extruded kibble with a surface temperature of 55°C and residual moisture 8%. This surface coating technique delivers 0.2 ppm trimethyl thiazole in the final kibble, operating two orders of magnitude below sensory off-flavour thresholds for companion animals as derived from two-bowl preference test methods adapted from the European Pet Food Industry Federation (FEDIAF) Guidelines on Nutrition. Coating adhesion is maintained by the triglyceride’s capillary draw into kibble surface micropores with average diameter 18–30 µm, measured by mercury intrusion porosimetry. Limitation: the presence of trace metal ions (Fe²⁺ above 2 mg/kg fat, released from worn carbon steel coater paddles) catalyses thiazole oxidation to the corresponding thiazole-N-oxide with a grassy aroma penalty; plants switch to 316L paddle inserts and monitor peroxide value weekly per AOCS Cd 8b-90 for the fat reservoir. The final articles include indoor-formula adult feline kibbles, high-protein freeze-dried raw-coated pieces, and veterinary dental chews where breath malodour counteraction is intended.

2,4,5-Trimethylthiazole (CAS 3581-91-7), a tri-substituted heterocyclic volatile, functions as a high-impact character impact compound for nutty, cocoa, and roasted profiles. Commercial supply is predominantly governed by synthesis via the Hantzsch thiazole route, condensing methyl α-bromoketones with thioamides under controlled reflux. The substance is listed as FEMA GRAS 3244 and carries the JECFA identifier 1038; the European Flavourings Database assigns it FL-no. 15.027. Standard production-grade material is offered at ≥98% purity (GC, area normalization), while a high-resolution variant for captive analytical standards is available at ≥99.5% with residual solvent levels below 100 ppm (ICH Q3C Class 3 solvents). Physical specifications: boiling point 167–168 °C at 760 mmHg, density 1.013–1.017 g/cm³ at 25 °C, refractive index n²⁰_D 1.504–1.508. Sensory detection threshold in water is consistently recorded between 0.01 and 0.05 µg/L, placing it among the most potent thiazole odorants in the flavorist’s palette.

Storage stability data from accelerated aging (40 °C/75% RH over 90 days) indicate that bulk 2,4,5-trimethylthiazole is prone to discoloration and sulfidic off-note formation when exposed to ambient light and headspace oxygen. Therefore, the compound is routinely packaged under nitrogen blanket in epoxy-phenolic lined steel drums or amber glass containers. Pre-drying with molecular sieve 4A is advised if moisture ingress exceeds 0.1% Karl Fischer titration.

Volatile Release Kinetics in Extruded Snack Matrices

In twin-screw extrusion with an L/D ratio of 32:1 and specific mechanical energy input of 120–160 Wh/kg, the survival rate of 2,4,5-trimethylthiazole through the die zone becomes a critical cost driver. At melt temperatures exceeding 140 °C, flash-off losses measured by headspace solid-phase microextraction (HS-SPME) coupled to GC-MS can exceed 45% of the nominal dosage. This contrasts sharply with 2-acetylthiazole, which exhibits higher thermal retention under the same shear profile. Process engineers often counter this by dosing the thiazole pre-blended into a lipid carrier (hydrogenated palm stearin, melting point 58–62 °C) immediately prior to the final barrel section, reducing vapor-pressure-driven losses to approximately 12–18% of the added flavor load. Post-extrusion, residual thiazole concentration in the expanded collet is typically quantified via ASTM E2881-18 methods, though interferences from pyrolysis products of corn-based substrates require selective ion monitoring at m/z 113 and 71.

Why Does 2,4,5-Trimethylthiazole Outperform Other Thiazoles in Roasted Nut Applications?

Thiazole derivatives differ dramatically in their aroma character and tenacity. A direct comparative analysis under matched matrix conditions reveals the following performance gaps:

Compound	Odor Character (10% in triacetin)	Threshold in oil (mg/kg)	Retronasal persistence (seconds)
2,4,5-Trimethylthiazole	Nutty, cocoa, roasted coffee, earthy	0.002–0.005	38–42
2-Isobutylthiazole	Green, tomato leaf, slight nutty	0.05–0.1	25–30
4-Methyl-5-vinylthiazole	Sulfurous, cocoa by-note	0.1–0.3	18–22
2-Acetylthiazole	Popcorn, cereal, roasted	0.5–1.0	22–28

The dominance of the trimethyl-substituted analogue in nut and cocoa profiles stems from a higher degree of alkyl branching adjacent to the nitrogen atom, which increases hydrophobicity (log P 2.1) and mucosal retention in the nasopharynx. In peanut butter emulsion systems (aqueous phase 16%, oil phase 84%), 2,4,5-trimethylthiazole at 0.5 ppm yields an aroma intensity comparable to 3.5 ppm of 2,4-dimethylthiazole, according to time-intensity profiling using a 15-point line scale per ISO 8586:2012 guidelines. The operational window is narrow: above 1.2 ppm in the finished biscuit, a distinct amine-like, fishy off-note emerges, attributed to trace formation of 2,4,5-trimethyl-3-thiazoline via reduction. Published data for quantifying this off-flavor threshold in high-temperature baked goods remains limited.

Without a preceding header, the following content addresses the practical handling and dilution protocols for compounding facilities. Neat 2,4,5-trimethylthiazole is a mobile liquid with a potent, penetrating odor; open-container handling in the compounding room without local exhaust ventilation (LEV) will rapidly exceed an internal olfactory fatigue limit, causing anosmia in operators within 2–3 minutes. Flavor houses routinely pre-dilute the raw material to a 1% (w/w) solution in triacetin or propylene glycol and store it in safety-coated, septum-capped amber vials at 4–8 °C. Dilution by mass, rather than volume, using a calibrated balance with 0.001 g readability is critical because the density of the concentrate shifts by 0.0009 g/cm³ per degree Celsius near room temperature. In beverage applications, pre-emulsification with gum acacia (E414) and ester gum (E445) at a 4:1 weighting ratio under high-pressure homogenization (250/50 bar two-stage) improves cloud stability and prevents ringing of the thiazole in the bottle headspace over a 9-month shelf life at 20 °C.

Regulatory and Toxicological Boundaries

Under 21 CFR 172.515, 2,4,5-trimethylthiazole is authorized as a synthetic flavoring substance for direct addition to food with no quantitative use limit provided it is employed in accordance with cGMP. The EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF) evaluated the substance in FGE.21 and assigned a margin of safety exceeding 10,000 based on a NOAEL of 150 mg/kg bw/day from a 90-day oral gavage study in rats. However, the flavorist must account for the total thiazole intake from multiple sources in a complex profile; the Joint FAO/WHO Expert Committee on Food Additives has specified an acceptable daily intake (ADI) of 0–0.5 mg/kg bw for the thiazole class as a group (JECFA 79th meeting). Consequently, in multi-source flavored systems (e.g., coffee + cocoa + caramel matrices), a cumulative contribution analysis is required to avoid exceeding the class-based ADI, especially for products targeting children aged 3–9 years where consumption factors are elevated.

Parameter	Specification	Method
Assay (anhydrous)	≥ 98.0%	GC-FID, internal standard
Water content	≤ 0.2%	Karl Fischer, coulometric
Refractive index (n²⁰_D)	1.503–1.509	ISO 280:1998
Acid value	≤ 1.0 mg KOH/g	ASTM D4659-14
Heavy metals (as Pb)	≤ 10 mg/kg	ICP-MS, EN 15763:2010
Arsenic	≤ 3 mg/kg	ICP-MS

Manufacturing Scale-Up Bottlenecks in Spray-Dried Encapsulates

When converting liquid flavor premixes containing 2,4,5-trimethylthiazole into shelf-stable powder carriers via spray drying, the inlet temperature differential between the atomized droplet surface and the drying air often triggers selective volatilization of the thiazole ahead of the carrier phase transition. Using a Niro FSD pilot dryer with a rotary atomizer operating at 18,000 rpm, the emulsion feed at 40% total solids (gum acacia/maltodextrin DE10 matrix) must not exceed an inlet temperature of 175 °C; losses at 190 °C escalate non-linearly from 8% to 34% of total aroma load. Outlet air temperature should plateau at 85–90 °C. A practical workaround involves a secondary post-drying fluidized bed coating with the same unconverted thiazole dissolved in a chilled (5 °C) ethanol solution at 0.02% weight gain, though this step must be documented as a processing aid if alcohol residues exceed 1000 ppm in the final powder. The resultant encapsulation efficiency, measured by total reconstituted aroma recovery at 40 °C in water, is typically 91–94%.

In shelf-life monitoring of roast-and-ground coffee fortified with 2,4,5-trimethylthiazole at 15 mg/kg green bean equivalent, GC-MS headspace quantification per ISO 20714:2019 demonstrates a first-order degradation half-life of 22 weeks in sealed foil-laminate packaging under nitrogen flush. In polyethylene-lined board cans with a simple glue seal, half-life plummets to 6 weeks, accompanied by a rise in 2,4,5-trimethylthiazole sulfoxide by-product at levels as high as 8 ppm, which imparts a distinct musty character. The incompatibility of 2,4,5-trimethylthiazole with amine-based Maillard reaction intermediates deserves emphasis; in paste-like bouillon concentrates that use hydrolyzed vegetable protein (HVP) with high free lysine content, the thiazole undergoes rapid Schiff base exchange, leading to a 60% sensory potency reduction within 48 hours at 30 °C, documented by triangle test difference evaluation (ISO 4120:2021).

HS Code	218905
Chemical Formula	C6H11NS
Molecular Weight	129.22 g/mol
Appearance	Colorless to pale yellow liquid
Odor	Nutty, roasted, meat - like odor
Boiling Point	148 - 150 °C
Solubility In Water	Slightly soluble
Solubility In Organic Solvents	Soluble in many organic solvents like ethanol, ether
Flash Point	41 °C
Density	1.025 - 1.035 g/cm³
Stability	Stable under normal conditions

Packing	100 - gram bottle packaging for Trimethyl Thiazole chemical.
Shipping	Trimethyl Thiazole, a chemical, is shipped in accordance with strict hazardous material regulations. It's packaged securely in suitable containers to prevent leakage during transport, ensuring safety throughout the shipping process.
Storage	Trimethyl thiazole should be stored in a cool, dry, well - ventilated area, away from heat sources and open flames due to its flammability. Keep it in a tightly sealed container to prevent vapor leakage. Store it separately from oxidizing agents and incompatible substances to avoid potential reactions. Follow proper labeling and safety procedures for easy identification and handling.

Trimethyl Thiazole