L-Cysteine Hydrochloride
Amino Acids
Nutritional Enhancers
Flavoring Agents
52-89-1 (anhydrous), 7048-04-6 (monohydrate)
E920
C₃H₈ClNO₂S (·H₂O for monohydrate)
$26.68 ~ $40.02
Food
Free sample from 100g(NF)
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Product Info
What is L-Cysteine Hydrochloride?
L-Cysteine Hydrochloride is a stable, crystalline salt form of the amino acid L-cysteine, primarily used in the food industry as a reducing agent to condition and relax dough and as a precursor for savory flavorings.
How is L-Cysteine Hydrochloride made?
| Step No. | Production Stage | Key Action | Control Point & Note |
|---|---|---|---|
| 1 | Raw Material Hydrolysis | Hydrolyzing a keratin source (e.g., duck feathers, hog bristles) with concentrated hydrochloric acid under heat. | Control Point: Acid concentration, temperature, and reaction time. Note: Ensures complete protein breakdown into constituent amino acids, including L-Cystine (a dimer of L-Cysteine). The quality of the raw material is critical. |
| 2 | Filtration & Decolorization | Filtering the hydrolysate to remove solid impurities, followed by treatment with activated carbon to remove color. | Control Point: Filter pore size and quantity of activated carbon. Note: This step is crucial for removing suspended solids and color bodies, significantly improving the purity of the intermediate solution. |
| 3 | Electrolytic Reduction | Reducing the L-Cystine in the solution to L-Cysteine using an electrolytic cell. | Control Point: Electric current density, voltage, temperature, and pH. Note: This is the most critical conversion step. Proper control is required to efficiently break the disulfide bond in L-Cystine to form two L-Cysteine molecules, maximizing yield. |
| 4 | Concentration & Crystallization | Concentrating the solution under vacuum and then cooling it under controlled conditions to precipitate L-Cysteine Hydrochloride crystals. | Control Point: Vacuum level, solution concentration, and cooling rate. Note: Slow, controlled cooling promotes the formation of large, pure crystals and minimizes the co-precipitation of impurities. |
| 5 | Separation & Washing | Separating the crude crystals from the mother liquor using a centrifuge and washing them with a small amount of cold water or solvent. | Control Point: Centrifuge speed and wash volume. Note: Efficiently removes the mother liquor, which contains a high concentration of impurities. Washing removes any remaining surface impurities from the crystals. |
| 6 | Drying & Sieving | Drying the washed crystals under vacuum at a low temperature to remove residual moisture. | Control Point: Drying temperature and vacuum pressure. Note: Gentle drying conditions are essential to prevent oxidation and degradation of the final product. Final moisture content must be strictly controlled. |
| 7 | Final Sieving & Packaging | Sieving the dried product to ensure uniform particle size and packaging it into sealed, airtight containers. | Control Point: Sieve mesh size and packaging environment integrity. Note: Ensures product meets physical specifications. Packaging is performed in a controlled, low-humidity environment to protect the hygroscopic product from moisture and contamination. |
Technical Specifications
| CAS Number | 52-89-1 (anhydrous), 7048-04-6 (monohydrate) |
| Chemical Formula | C₃H₈ClNO₂S (·H₂O for monohydrate) |
| Solubility | Highly soluble in water (up to 1 M, ~157 g/L), soluble in ethanol, acetone; insoluble in non‑polar solvents |
| Storage Conditions | Cool, dry, inert atmosphere; avoid light, air, moisture |
| Shelf Life | 24 Months |
Applications & Usage
Common Applications:
Food (flavor precursor
antioxidant)
flour treatment
pharmaceuticals
cosmetics
cell culture media
Mechanism of action:
| Parameter | L-Cysteine Hydrochloride |
|---|---|
| Functional Category | Dough Conditioner; Reducing Agent; Flavor Precursor |
| Key Ingredients | L-Cysteine Hydrochloride (Anhydrous or Monohydrate) |
| Mechanism of Action | Functions as a reducing agent by cleaving disulfide bonds (-S-S-) within the gluten protein network via thiol-disulfide exchange. This reaction reduces the dough's elastic modulus and viscosity, breaking down the protein matrix into smaller, more mobile units. Also serves as a precursor in Maillard reactions, contributing to the formation of savory and meaty flavor compounds. |
| Application Effect in Product | Reduces dough mixing time and improves machinability/extensibility in baked goods (e.g., bread, pizza crusts). Increases final product volume and creates a finer, more uniform crumb structure. Generates characteristic savory (umami) and roasted meat flavors when heated in flavor systems. |
Comparison:
| Product Name | Category/Type | Key Features | Strengths (vs peers) | Weaknesses (vs peers) | Best Use Cases | Why Choose |
|---|---|---|---|---|---|---|
| L-Cysteine Hydrochloride | Amino Acid Salt | A stable, water-soluble salt of the amino acid L-cysteine. Direct precursor to glutathione. | More stable and soluble than free-form L-cysteine. Cost-effective. | Less bioavailable and stable than NAC for supplementation. Not an essential amino acid. | Food additive (dough conditioner), pharmaceutical production, basic dietary supplementation. | For a direct, stable, and economical source of cysteine, especially in industrial or food applications. |
| N-Acetylcysteine (NAC) | Amino Acid Derivative | Acetylated, highly stable form of cysteine. A powerful antioxidant and mucolytic agent. | Superior stability and bioavailability for raising glutathione levels. Extensively researched for health benefits. | Primarily a supplement or medication, not a food additive. Can have a strong sulfur odor. | Dietary supplementation for antioxidant support, respiratory health, and liver protection. | When the primary goal is to effectively raise systemic glutathione levels for health purposes. |
| L-Cysteine (Free Form) | Amino Acid | The fundamental, non-essential sulfur-containing amino acid. | Provides the pure amino acid without the hydrochloride component. | Relatively unstable; easily oxidizes to cystine, reducing its effectiveness and shelf-life. | Laboratory research and specific chemical syntheses where the salt form is undesirable. | For applications requiring the pure, unbound amino acid where long-term stability is not critical. |
| L-Methionine | Essential Amino Acid | An essential amino acid that serves as a metabolic precursor to cysteine in the body. | Fulfills the dietary requirement for an essential amino acid. Supports methylation pathways. | Indirect source; conversion to cysteine requires multiple enzymatic steps and vitamin cofactors. | Supplementing to correct a dietary deficiency of an essential amino acid. | To address a broader nutritional need for an essential amino acid that also serves as a cysteine precursor. |
| L-Glutathione | Tripeptide Antioxidant | The "master antioxidant" that L-cysteine helps the body produce. | Provides the final, active antioxidant molecule directly, bypassing the synthesis steps. | Very poor oral bioavailability; most is broken down by digestion before absorption. Significantly more expensive. | Specialized liposomal or sublingual supplements, or intravenous use in clinical settings. | For specialized delivery methods intended to bypass poor gut absorption, though precursors are often more effective orally. |
Technical Documents
Available Documentation
COA, MSDS, monograph certificate
Safety Data Sheet (SDS)
Provided
Certificate of Analysis (COA)
Quality assurance documentation
Technical Data Sheet
Detailed technical specifications