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L-Threonine, known as L-Threonin in Turkish, is a proteinogenic and essential α-amino acid with the molecular formula C₄H₉NO₃. This compound, defined by CAS No 72-19-5; It is an important nutritional raw material used in human and animal nutrition, feed formulation, food, nutritional supplement and pharmaceutical grade amino acid applications.
The L-Threonine molecule carries a α-amino group, a carboxylic acid group, and a hydroxyl group on the side chain. This hydroxyl function positions L-Threonine between polar, uncharged side chain-bearing amino acids along with serine, and contributes to hydrogen bonding, polar interaction, and enzymatic modification behaviors in the protein.
The molecular weight of L-Threonine is approximately 119.12 g/mol. The molecule has two chiral centers, and the biologically used natural form of L-Threonine is systematically identified as (2S,3R)-2-amino-3-hydroxybutanoic acid.
L-Threonine is one of the important crystalline amino acids used to balance the feed protein profile, especially in animal nutrition. When there is a difference between the actual need and the amount of threonine from natural raw materials in cereal and vegetable protein-based rations, the addition of pure L-Threonine allows the amino acid balance of the formulation to be precisely adjusted.
The use of L-Threonine is particularly important in low crude protein feed concepts. Adding limiting amino acids at targeted levels, rather than simply increasing the total crude protein content, can help improve nitrogen utilization efficiency and reduce unnecessary protein surplus.
L-Threonine can also be used in food applications. The U.S. FDA registers L-Threonine with its technical functions as a nutrient supplement, flavor enhancer and flavoring agent or adjuvant and verifies its CAS 72-19-5 identity.
Food, feed, pharmaceutical, and laboratory grades for L-Threonine may have the same CAS number but are not the same product. Purity, microbiological criteria, heavy metal limits, endotoxin, remaining manufacturing ingredients, particle characteristics, and pharmacopoeia/FCC compliance may differ by area of use.
L-Threonine is produced on a commercial scale mostly by microbial fermentation. Since the production organism used may vary depending on the producer and commercial grade, the production microorganism or GMO status should not be generalized by looking only at the expression "fermentation product".
L-Threonine is available as a white crystal or crystalline powder and shows high solubility in water. PubChem reports a water solubility of 97 g/L at about 25 °C, while Evonik's current feed type ThreAMINO® white paper gives a value of 90 g/L at about 20 °C; this difference should be considered as representative values depending on purity, measurement condition and commercial grade.
L-Threonine is involved in the formation of collagen, elastin, and muscle tissue. L-Threonine supports immune function by contributing to the production of antibodies and mucin synthesis in the gastrointestinal tract. L-TRREONINE plays a crucial role in fat metabolism and helps prevent fatty liver accumulation.
L-Threonine is involved in central metabolic pathways, including glycine and serine biosynthesis.
L-Threonine serves as a precursor for neurotransmitter-related molecules and supports nervous system function. It contributes to nitrogen balance and overall protein turnover in the body. L-Threonine is an essential α-amino acid that plays a critical role in protein synthesis and normal metabolic function in humans and animals.
L-Threonine contains a hydroxyl functional group in its side chain; this group contributes to hydroxene bonds and structural stability in proteins.
L-Threonine occurs naturally in the L-configuration, its biologically active form incorporated into proteins.
When purchasing L-Threonine, the choice should not be made solely on the basis of amino acid name or price. Assay, L-isomer purity, moisture, ash, heavy metal, microbiological quality, particle size, solubility, pharmacopoeia/FCC or feed regulatory compliance and batch COA information should be evaluated together according to the target area of use.
WHAT IS L-THREONINE?
L-Threonine is a natural L-configuration α-amino acid used in protein synthesis. It is chemically defined as (2S,3R)-2-amino-3-hydroxybutanoic acid.
L-Threonine appears as a white, crystalline powder with a slightly sweet taste and high water solubility. L-Threonine dissolves poorly in most organic solvents and remains chemically stable under normal dry storage conditions.
L-Threonine exhibits zwitterionic behavior in aqueous solutions depending on the pH.
L-Threonine is widely used as a dietary supplement in human health products and fortified foods. It is widely added to animal feed; thus, improving growth performance and feed efficiency in animals and poultry. It is also applied in drug research, biotechnology, and cell culture media formulation.
L-Threonine is an amino acid used in the biosynthesis of proteins. It contains a α-amino group found in protonated −NH+
A side chain containing L - Treonin and a hydroxyl group is present; this makes it a polar, uncharged amino acid.
L-Threonine is essential in humans, that is, the body cannot synthesize it: it must be obtained from the diet.
L-Threonine is synthesized from aspartate in bacteria such as E. coli. It is encoded by all codons (ACU, ACC, ACA, and ACG) starting from AC.
L-Threonine is an essential amino acid. Amino acids are the building blocks of proteins.
It cannot be produced by the body and must be consumed in food. L-Threonine is an amino acid used in the biosynthesis of proteins.
L-Threonine contains a side chain containing an α-amino group, a carboxyl group, and a hydroxyl group; this makes it a polar, uncharged amino acid.
L-Threonine is essential in humans, that is, the body cannot synthesize it: it must be obtained from the diet.
L-Threonine is synthesized from aspartate in bacteria such as E. coli. L-Threonine is encoded by all codons starting from AC.
The isolation of L-Threonine and the identification of Threonine from the hydrolysate fiber protein by W. C. Rose in 1935 proved that it was the last essential amino acid.
L-Threonine plays extremely important physiological role in animals because it is the second or third limiting amino acid for animals.
Things like promoting growth, boosting immune function, etc. A carboxylic acid group is present in the molecule. An amino group is present on the same α-carbon. And the side chain is in the structure of -CH(OH)-CH₃.
L-Threonine is based on bioengineering principles through underwater fermentation using corn starch and other raw materials, refined and produced feed additives.
L-Threonine can adjust the amino acid balance in feed, promote growth, improve meat quality, and increase the value of feed raw materials with low amino acid digestibility, produce low-protein feed, save protein resources, reduce the cost of feed ingredients, reduce the nitrogen content of manure and urine, and reduce the concentration and release rate of animal building ammonia.
L-Threonine has been used to widely add to pig food, chicken food, shrimp feed, and snake bam feed.
L-Threonine cannot be synthesized by animals, but L-Threonine is an essential amino acid to fully balance the composition of amino acids to meet the need for animal growth, increase weight and lean meat, and reduce feed conversion.
L-Threonine can also increase the value of feed raw materials with lower amino acid digestibility and improve the production performance of low-energy feeds.
L-Threonine can lower feed crude protein levels, improve feed nitrogen utilization, and reduce feed costs.
So, Threonine can be used for pigs, chickens, ducks, and old aquaculture and farming. The hydroxyl group present in this side chain gives the molecule a polar character
The molecular formula of L-Threonine is C₄H₉NO₃. Its molecular weight is about 119.12 g/mol, CAS No is 72-19-5, PubChem CID is 6288, UNII code in FDA's GSRS system is 2ZD004190S.
L-Threonine is a proteinogenic amino acid. This statement indicates that it is one of the standard amino acids that is directly incorporated into protein synthesis through the genetic code.
It is an essential amino acid in human nutrition.
Since the body cannot meet its L-Threonine needs with sufficient de novo synthesis, it must be obtained from food.
The requirement for threonine in animal nutrition depends on species, growth period, physiological state, total feed protein and other amino acid levels. Therefore, there is no "single universal percentage of L-Threonine use" in feed applications.
COMMON PRODUCT AND CHEMICAL NAMES
L-Threonine
L-Threonine
Threonine
(2S,3R)-2-Amino-3-hydroxybutanoic Acid
L-2-Amino-3-hydroxybutanoic Acid
Thr
L-Thr
CAS 72-19-5
PubChem CID 6288
CAS NO, EC / EINECS NO AND CHEMICAL IDENTIFICATION
Product Name: L-Threonine
English name: L-Threonine
Systematic name: (2S,3R)-2-Amino-3-hydroxybutanoic Acid
Chemical class: α-Amino acid
Subclass: Polar, uncharged side-chain proteinogenic amino acid
CAS No: 72-19-5
PubChem CID: 6288
UNII: 2ZD004190S
Molecular formula: C₄H₉NO₃
Molecular weight: Approximately 119.12 g/mol
Number of chiral centers: 2
Natural biological configuration: L-Threonine, (2S,3R)
Physical form: White crystal or crystalline powder
Water solubility: Approx. 90–97 g/L, with representative values around 20–25 °C
Solubility in alcohol: Practically insoluble / very low
Solubility in ether: Insoluble
Solubility in chloroform: Insoluble
Melting behavior: With degradation around 256 °C
Carboxyl pKa value: Approximately 2.63
Amino group pKa value: Approximately 10.43
Form at room temperature: Solid
Volatility: Very low
Main nutritional function: Source of essential amino acids
CHEMICAL STRUCTURE AND MOLECULAR PROPERTIES OF L-THREONINE
The main skeleton of L-Threonine, as in all α-amino acids, is organized over the central α-carbon.
The amino group is attached to this carbon. The carboxylic acid group is attached.
A hydrogen atom is bonded. The fourth bond goes to the characteristic side chain.
The L-Threonine side chain is -CH(OH)-CH₃. The second carbon in the side chain is also the chiral center.
Therefore, Threonine carries two stereogenic centers, unlike many amino acids with a single stereocenter.
The biological form of L-Threonine is in the (2S,3R) configuration. Stereochemistry is critical for nutrition and biochemistry.
Protein synthesis systems distinguish the stereochemistry of amino acids.
Therefore, L-isomer purity is the important quality criterion for food, feed and pharmaceutical use.
The hydroxyl group in the molecule can participate in polar interactions as hydrogen bond donor and acceptor.
Amino and carboxyl groups can be ionized in aqueous media.
This property explains L-Threonine's strong interaction with water.
The XLogP value of the molecule is very low.
In the PubChem calculation, XLogP3 is given as approximately -2.9. This value supports the fact that the compound shows a significant tendency to the water phase compared to the hydrophobic organic phases.
The topological polar surface area is calculated to be about 83.6 Ų. The molecule has three hydrogen bond donors and four hydrogen bond acceptors.
This high polar function density is also one of the main reasons for water solubility.
L-Threonine can show ionic/zwitterionic character in crystalline form. In solid crystal structure, there are electrostatic interactions between amino and carboxylate groups.
Due to this strong crystalline lattice, high temperature decomposition behavior is observed instead of boiling. The FCC reports melting behavior for L-Threonine with decay at approximately 256 °C.
The prominent properties of L-Threonine at the chemical and molecular level are as follows:
α-Carrying amino acid structure
Having two chiral centers
Being in a natural L-configuration
Carrying hydroxyl group on the side chain
Showing polar character
Creating a zwitterion
Showing high solubility in water
Participate in protein synthesis
Acting as a nutritional essential amino acid
To be used as crystal raw material in different quality grades
PHYSICAL AND CHEMICAL PROPERTIES OF L-THREONINE
L-Threonine is a white crystalline solid under normal conditions.
Due to its high polarity and ionic character, it dissolves well in water while showing low solubility in nonpolar or low-polarity organic solvents.
General technical specifications:
Physical appearance: White crystal or crystalline powder
Chemical class: α-Amino acid
Molecular formula: C₄H₉NO₃
Molecular weight: Approximately 119.12 g/mol
CAS No: 72-19-5
PubChem CID: 6288
UNII: 2ZD004190S
Stereochemistry: (2S,3R)
Water solubility: About 97 g/L, 25 °C
Evonik feed-grade technical value: Approx. 90 g/L, 20 °C
Solubility in alcohol: Insoluble or very low
Solubility in ether: Insoluble
Solubility in chloroform: Insoluble
Melting/decomposition: Approx. 256°C
Carboxyl pKa: Approximately 2.63
Amino pKa: Approximately 10.43
XLogP3: Approx. -2.9
Topological polar surface area: Approx. 83.6 Ų
Volatility: Negligible
Commercial feed-grade assay example: Minimum 98.5%
Feed-grade ash sample: 0.5% maximum
Example of feed-grade loss on drying: Maximum 0.5%
Evonik ThreAMINO granule appearance: White to light brown granule
Evonik ThreAMINO granule bulk density: Approx. 730 kg/m³ ± 10%
Evonik ThreAMINO powder bulk density: Approx. 650 kg/m³ ± 15%
These latter values are not universal properties of the L-Threonine molecule.
Technical specifications of specific Evonik ThreAMINO Feed Grade.
L-Threonine from another manufacturer may have different bulk density, color tone, particle distribution or flow characteristics.
Manufacturer specifications must therefore be separated from the general physical constants of the chemical.
In particular, bulk density is more important in terms of logistics, silo capacity, dosing system and premix homogeneity than formulation.
Particle size, on the other hand, can affect dusting, segregation, and automated dosing behavior.
HOW DOES L-THREONINE WORK AT THE MOLECULAR LEVEL?
Central to L-Threonine's biological function is protein synthesis. During protein synthesis, cells incorporate amino acids into the polypeptide chain in the order determined by the genetic code.
When Threonine codons are read by the ribosome, L-Threonine is added to the chain via the appropriate aminoacyl-tRNA. When an amino acid is below the requirement, protein synthesis capacity may be limited by this deficiency. Therefore, amino acid balance in nutrition is a more detailed concept than just the total amount of protein.
The basic working principle of L-Threonine addition in feed formulation is to directly provide the missing nutritional amino acid.
For example, even if the ration contains the required total protein, the level of digestible threonine may remain below the target. In this case, the concentration of threonine can be made more balanced with other amino acids by adding crystalline L-Threonine.
As a result, the need to provide unnecessary protein surplus of other amino acids can be reduced.
This approach is particularly important in low-protein ration design.
Evonik positions crystalline L-Threonine supplementation with the aim of improving amino acid balance in low-protein pork, broiler and laying hen diets.
The manufacturer also states that correct amino acid balancing can contribute to reducing nitrogen excretion while supporting feed utilization and growth performance.
This benefit is not due to the fact that L-Threonine is a "growth stimulant" alone. It is due to establishing a more accurate nutrient balance.
The side chain hydroxyl group of L-Threonine in the protein is also important at the molecular level. It can participate in hydrogen bond networks.
It can affect the local polarity of the protein. It can become a phosphorylation site in enzyme and signaling proteins.
However, the primary technical function of commercial L-Threonine as a feed or food raw material is not to directly manipulate these cellular details, but to provide nutritional L-Threonine.
The main functions of L-Threonine at the molecular and nutritional level are:
Providing the building block for protein synthesis
Meeting the requirement of essential amino acids
Balancing feed amino acid profile
Reducing limiting amino acid deficiency
Supporting low-protein feed strategies
Helping to reduce unnecessary nitrogen load
Providing nutritional amino acids in food and supplement systems
To provide polar hydroxyl function in protein structure
To create amino acid residue suitable for phosphorylation in biological proteins
IN WHICH SECTORS IS L-THREONINE USED?
The most important commercial uses of L-Threonine are in the animal nutrition, food and nutritional supplement sectors.
Main areas of use:
Animal feeds
Premixes
Poultry feeds
Broiler feeds
Laying hen feeds
Pig feeds
Piglet feeds
Low protein rations
Amino acid balanced rations
Pet food formulations
Aquaculture feeds
Special animal feeding systems
Feed concentrates
Food-grade amino acid blends
Nutritional supplements
Amino acid drinks
Sports nutrition products
Medical nutrition products
Protein/amino acid blends
Food nutrient enrichment systems
Aroma and flavor systems
Pharmaceutical raw material grades
Amino acid preparations
Laboratory reagents
Biotechnological environments
Fermentation and cell culture research systems
The target application of L-Threonine is directly determinant in grade selection.
The feed-grade product is not automatically suitable for use in food supplements.
The food-grade product is also not automatically suitable for pharmaceutical use.
Exact monograph compliance should be verified in applications with USP, EP or other pharmacopoeia requirements.
ANIMAL NUTRITION AND FEED APPLICATIONS OF L-THREONINE
Animal nutrition is one of the most important industrial applications of L-Threonine in terms of volume.
The aim of feed formulation is to meet the digestible amino acid requirement of the animal, not just the crude protein requirement.
L-Threonine is used for this purpose as a concentrated source of nutritional amino acids.
The possible functions of L-Threonine in feed applications are:
Completing the ration threonine level
Balancing the amino acid profile
Addressing limiting threonine deficiency
Developing a low-protein diet
Optimizing the use of protein feedstock
Supporting nitrogen utilization efficiency
Helping to reduce nitrogen excretion
Balancing poultry growth rations
Balancing laying hen rations
Balancing pig rations
Improving amino acid profile in piglet feeds
Completing pet food amino acid goals
Providing amino acid source in the production of premixes and concentrates
According to Evonik's current ThreAMINO product information, feed-grade L-Threonine is offered with a minimum assay of 98.5%.
The manufacturer states that the threonine deficiency of grain-based feeds in low-protein pig, broiler and laying hen rations can be supplemented with crystalline L-Threonine.
This approach is important for nutrition. Corn, wheat, soybean flour or other raw materials have different amino acid profiles. The total protein percentage of the feed does not guarantee that all the necessary amino acids are present in the correct ratio.
During formulation, ingestible lysine, methionine+cystine, threonine, tryptophan and other amino acids are evaluated together.
The level of L-Threonine can often be optimized over ideal protein ratios based on the target lysine level.
However, these rates vary depending on the animal species, age, genetics, performance goal and nutritional system used.
For this reason, it is not correct to give a "standard dosage of L-Threonine".
The feed formulator should calculate the need according to the amino acid analysis of the actual raw materials and the target nutrient specification.
Crystalline L-Threonine allows for more precise amino acid balancing, especially in low-protein rations.
In high crude protein rations, excess amino acids need to be metabolized.
Some of the nitrogen is excreted from the body.
More targeted amino acid feeding may make it possible to reduce unnecessary protein surplus.
This approach can provide advantages in terms of feed cost and environmental nitrogen load.
In the EFSA feed additive system, amino acids are evaluated in the nutritional additives category. For a specific L-Threonine feed additive product to be placed on the market in the European Union, the production organism, purity, user safety and authorization status should be checked on an exact product basis.
USES OF L-THREONINE IN FOOD, NUTRITIONAL SUPPLEMENTATION, AND NUTRITIONAL APPLICATIONS
L-Threonine can be used as a nutritional amino acid in the food and nutritional supplement industry.
In the US FDA Substances Added to Food database, L-Threonine is listed with three technical functions:
Flavor enhancer
Flavoring agent or adjuvant
Nutrient supplement
The FDA gives CAS No 72-19-5 and reference 21 CFR 172.320 in the same registration.
FEMA No 4710 and JECFA flavor number 2119 information are also included in the FDA register.
Food-grade L-Threonine can be used in food formulation to increase amino acid nutritional content.
It can be formulated together with other amino acids in amino acid blend products.
It can be used in powdered beverage mixes.
It can be used in special nutrition products.
In nutritional supplements, it can be part of a single amino acid or multiple amino acid formula.
However, the level of use should be determined according to the target consumer group of the product and the legislation of the relevant country.
The phrase "L-Threonine can be used in food" does not mean unlimited and free use in every product.
Legislation for the target country and food category must be verified.
Food Chemicals Codex offers a quality monograph for L-Threonine.
In the FCC designation, the product is given as a white crystalline powder.
It dissolves easily in water.
It is insoluble in alcohol, ether and chloroform.
It melts by decomposition at about 256 °C.
For the food manufacturer, purchasing an FCC-compliant product provides a more reliable quality approach than selecting products based solely on chemical identity.
However, the existence of the FCC monograph does not mean that a product can be legally used in all markets. The USP also clearly states this.
The final food producer must also verify compliance with the target legislation.
IS L-THREONINE USED IN FOOD, COSMETICS AND PHARMACEUTICAL APPLICATIONS?
L-Threonine is the defined amino acid that can be used in food and nutritional supplements.
FDA records include nutrient supplement and flavoring functions. Food-grade quality should be selected for food use.
Even if the feed-grade product contains the same chemical molecule, it should not automatically be considered suitable for use in food production.
L-Threonine is also defined in pharmaceutical standards.
There are matches for USP, EP, and other pharmacopoeia references for L-Threonine in FDA GSRS records.
The USP Threonine monograph specifies a range of 98.5–101.5% L-Threonine on a dry basis.
This information indicates that there is a pharmacopoeia standard in terms of pharmaceutical quality control.
However, just because L-Threonine has a USP monograph does not mean that a particular commercial product is automatically approved for drug use.
GMP, manufacturer quality system, pharmacopeia tests, impurity profile and target preparation legislation should be evaluated separately.
In the cosmetic field, L-Threonine can be seen in amino acid-based formulations or skin/hair conditioning concepts.
However, L-Threonine's most important commercial uses are nutrition, feed, and food rather than cosmetics.
If cosmetic use is targeted, INCI and the target country cosmetic legislation should be verified separately.
L-Threonine should not be considered directly as an "active drug". If it is to be used in a pharmaceutical or medical nutrition product, suitability should be evaluated based on the product class and intended use.
INDUSTRIAL APPLICATIONS OF L-THREONINE
L-Threonine is mainly used in industry in the form of a high-purity crystalline amino acid produced by controlled fermentation.
The following functions may be prominent in industrial L-Threonine applications:
Feed amino acid balancing
Feed-grade premix production
Optimization of poultry feeds
Optimization of pig feeds
Low-protein feed development
Pet food amino acid balancing
Production of amino acid concentrate
Food-grade amino acid mixture preparation
Nutrient supplement production
Sports nutrition product development
Preparation of medical nutrition mixture
Use of amino acids in flavor systems
Pharmacopoeia quality raw material production
Laboratory reagent
Microbial fermentation media
Biotechnology and research environments
Premix uniformity is important because L-Threonine can be used in small dosages in dry mixes.
Segregation can occur when the particle size is very different from other feed or food ingredients.
Fine powder product may create more dust during transfer.
Granular products can provide the advantage of better flow and low dusting in some feed plants.
Evonik therefore characterizes ThreAMINO® in its physical forms as granules and powders.
A bulk density of approximately 730 kg/m³ is reported for the granular product.
A value of approximately 650 kg/m³ is given for powder.
This difference is significant in terms of silo volume and dosing equipment.
If L-Threonine is to be used in aqueous premix or liquid applications, solubility should be checked.
Room temperature water solubility of approximately 90–97 g/L may be the practical limit in concentrated solutions.
At higher target concentrations, temperature, pH, and other dissolved substances can alter solubility.
The risk of crystallization should be evaluated separately in low-temperature storage.
The following issues should be evaluated in the use of L-Threonine in industrial systems:
L-isomer ID
Assay
Nem / loss on drying
Ash
If sulfated ash is required, the relevant limit
Heavy metal limits
Arsenic
Lead
Cadmium
Mercury
Microbiological quality
Production organism
Fermentation production information
Relevant documentation if GMO declaration is required
Particle size
Bulk density
Streaming features
Dusting
Solubility
Color
Smell
Premix homogeneity
Stability
Shelf life
TDS
SDS
COA
FCC/USP/EP or feed authorization documents
WHAT PROBLEMS CAN L-THREONINE HELP SOLVE?
L-Threonine can help solve technical problems such as amino acid imbalance, unnecessarily high crude protein requirement and limiting threonine level, especially in nutrition and feed formulation.
Threonine level in feed below target
If the digestible threonine from natural protein raw materials is insufficient, crystalline L-Threonine can directly help to supplement the missing amount.
Difficulty in designing a low-protein ration
When the crude protein level is reduced, some essential amino acids may fall below the requirement.
Crystalline L-Threonine, along with other amino acids, helps to precisely supplement these deficiencies.
Unnecessarily high use of soy or protein raw materials
If the ration requires high protein raw materials for only one or a few amino acids, amino acid supplementation can allow for more precise nutrient balancing.
High nitrogen excretion
Reducing protein consumption above the need and balancing essential amino acids can help improve nitrogen use efficiency.
Low active concentration in the premix
High assay L-Threonine provides high active amino acid input with a small amount of product.
Insufficient threonine in food-grade amino acid mixture
Food-grade L-Threonine can help bring the total amino acid composition to the target profile.
Insolubility in amino acid solution
In this case, adding more products is not the right solution.
Temperature, total dissolved solids, amount of water, and pH should be re-evaluated.
Segregation in premix
Particle size, bulk density and mixing sequence should be optimized.
Simply changing the amount of L-Threonine will not solve the homogeneity problem.
Performance problem in feed
Not every performance problem is due to threonine deficiency.
Energy, lysine, methionine, tryptophan, minerals, vitamins, digestive health and feed quality should be evaluated together.
Therefore, L-Threonine should be used as a targeted amino acid fix in the nutrition program.
THINGS TO CONSIDER WHEN USING L-THREONINE
Grade, stereochemistry, assay and target application legislation are the basic technical criteria for the use of L-Threonine.
The following issues should be considered when using L-Threonine:
CAS Number must be verified.
It should be verified that it is an L-isomer.
Confusion with D-Threonine or allothreonine should be avoided.
Assay should be checked.
The amount of moisture should be controlled.
The amount of ash should be controlled.
Food-grade, feed-grade or pharma-grade distinction should be made.
If there is an FCC requirement, it should be verified.
If there is a USP or EP requirement, it should be verified.
Feed authorization documents should be checked.
If the production microorganism is required, it should be verified.
Fermentation production information should be examined.
GMO declaration should be evaluated according to the target market.
The particle size should be controlled.
Bulk density should be examined.
Dusting should be evaluated.
Premix homogeneity should be tested.
Water solubility should be considered.
Crystallization should be checked in concentrated solutions.
Microbiological quality should be verified against the target application.
Heavy metal limits should be checked.
TDS should be examined.
SDS should be examined.
The COA should be checked.
Legislation should be verified according to the target country.
The amount of L-Threonine in feed formulation should not be determined only by a fixed percentage based on total feed tonnage.
The actual threonine requirement and the digestible threonine from the raw materials must be calculated.
In nutritional supplement or food formulation, the amount of use should be evaluated together with the target daily consumption, serving size and product category.
INITIAL FORMULATION APPROACHES FOR L-THREONINE
The following examples are initial approaches prepared to show how L-Threonine can be evaluated in feed, food and liquid systems.
These are not verified commercial feed prescriptions, medical dosing recommendations, or final food formulas.
The actual levels must be calculated by the nutritionist according to the species, age, ration and target legislation.
EXAMPLE 1: L-THREONINE LOW PROTEIN FEED FORMULATION SCREENING
Purpose: To evaluate the effect of maintaining the digestible threonine target with crystalline L-Threonine on feed amino acid balance while reducing crude protein.
Starting components:
Grain component: 58.0%
Protein raw material: 25.0%
L-Lysine source: 0.6%
DL-Methionine or suitable source of methionine: 0.3%
L-Threonine: 0.2%
L-Tryptophan: 0.1%
Vitamin-mineral premix: 1.0%
Energy sources: 14.8%
Total: 100%
Application approach:
The actual amino acid matrix of the raw materials is determined.
The target digestible lysine level is determined.
The threonine target is calculated based on the nutritional standard used.
The amount of threonine from raw materials is calculated.
The missing part is completed with crystalline L-Threonine.
It is confirmed that other essential amino acids are also not under the requirement.
The crude protein level is checked.
The balance of energy and minerals is reaffirmed.
Premix homogeneity is evaluated.
The laboratory feed is checked by amino acid analysis.
Controlled feeding performance test is carried out under appropriate conditions.
EXAMPLE 2: L-THREONINE FOOD-GRADE AMINO ACID POWDER MIX
Purpose: To evaluate the solubility, taste, and physical stability of L-Threonine in a dry powder mixture with different amino acids.
Starting components:
Food-grade L-Threonine: 10.0%
Other food-grade amino acids: 55.0%
Acidity regulator: 4.0%
Aroma system: 5.0%
Sweetener: 2.0%
Carrier: 23.0%
Anti-caking: 1.0%
Total: 100%
Application approach:
The assay values of all amino acids are taken from COA.
Target active amounts per serving are calculated.
Particle sizes are compared.
The risk of segregation is examined.
Dry mix homogeneity is tested.
It is added to the standard portion of water.
Dissolution time is measured.
Clarity and sediment are checked.
The taste profile is evaluated.
Moisture and accelerated stability are applied.
Final label and regulatory compliance are verified separately.
EXAMPLE 3: L-THREONINE AQUEOUS CONCENTRATED SOLUTION SCREENING
Purpose: To evaluate the practical solubility and low-temperature crystallization behavior of L-Threonine in liquid premix or process solution.
Starting components:
Deionized water: 90.0%
L-Threonine: 9.0%
pH regulator: 0.5%
Protective system: 0.5%
Total: 100%
Application approach:
The water is brought to a constant temperature.
L-Threonine is added gradually.
At each level, the time to complete dissolution is measured.
The pH value of the solution is recorded.
Clarity is monitored at room temperature.
Storage test is performed at 5 °C.
Crystal formation is controlled.
The re-dissolution behavior is evaluated upon return to 25 °C.
The target concentration is selected based on the actual process temperature.
ALTERNATIVES AND COMPARISON OF L-THREONINE
It is not enough to be in the "amino acid" class when determining the alternative for L-Threonine.
The biological function and nutritional requirements of each amino acid are different.
One amino acid is not a direct replacement for another essential amino acid.
L-THREONINE AND L-LYSINE
L-Lysine and L-Threonine are different essential amino acids.
In feed formulation, both are important parts of amino acid balance.
Lysine is used as a reference amino acid in most ideal protein systems.
Threonine requirement is often assessed in proportion to the target lysine level.
L-Lysine deficiency cannot be corrected by the addition of L-Threonine.
L-Threonine deficiency also cannot be compensated for by lysine.
Therefore, the two products are complementary nutritional components, not alternatives.
L-THREONINE AND DL-METHIONINE
Methionine and threonine have different metabolic and protein structural roles.
DL-Methionine is one of the important sources of amino acids, especially in poultry rations.
L-Threonine is a separate amino acid required in a different ideal protein ratio.
Both products can be used together for precise amino acid balancing of low-protein rations.
It is not possible to substitute them one-to-one.
L-THREONINE AND L-TRYPTOPHAN
L-Tryptophan is the essential amino acid that carries the aromatic indole side chain.
L-Threonine, on the other hand, is a polar amino acid with a hydroxyl group.
Their nutritional requirements and natural levels in the feed are different.
In low-protein rations, the level of both should be checked separately.
A deficiency in one cannot be eliminated by more than the other.
L-THREONINE AND L-SERINE
L-Serine and L-Threonine are structurally similar amino acids that carry a hydroxyl group in the side chain.
The Serine side chain is -CH₂OH.
The threonine side chain is in the -CH(OH)CH₃ structure.
L-Threonine is an essential amino acid in the human diet, while serine is generally considered a non-essential amino acid.
Therefore, their biological and nutritional functions are not the same.
They should not be used interchangeably in the formulation.
L-THREONINE AND DL-THREONINE
L-Threonine is the stereochemical form used in natural protein synthesis.
DL-Threonine refers to the mixture of L- and D-isomers.
In terms of nutrition and biological use, the two products should not be considered equivalent.
It is important to use standardized L-Threonine in feed, food, and pharmaceutical applications.
The stereoisomer must be explicitly verified at the time of purchase.
QUALITY CONTROL AND PURCHASING CRITERIA FOR L-THREONINE
When purchasing L-Threonine, the sector in which it will be used and the desired quality standard should be determined first.
The difference between feed-grade and food-grade is not just assay.
Recommended information to review before purchasing:
Product Name
Manufacturer
L-isomer ID
CAS No
Molecular formula
Assay
Dry base assay
Loss on drying
Humidity
Ash
If sulfated ash is required
Specific rotation
Optical purity
D-Threonine limit
Other amino acid impurities
Fermentation by-products
Heavy metals
Lead
Arsenic
Cadmium
Mercury
Microbiological limits
Total aerobic load
Yeast and mold
Salmonella
E. coli
Particle size
Granular or powder form
Bulk density
Streaming features
Color
Smell
Water solubility
Production method
Fermentation organism
If GMO status / declaration is required
Feed authorization
FCC compliance
USP compliance
EP eligibility
GMP requirement
If FSSC/ISO/HACCP documents are required
Shelf life
Packaging
Batch number
Production date
Origin
TDS
SDS
COA
In the case of Evonik ThreAMINO Feed Grade, the assay is a minimum of 98.5%.
Ash is a maximum of 0.5%.
Loss on drying is a maximum of 0.5%.
These values are not the universal limit for all L-Threonine products.
The specific feed-grade is the specification of the product.
The USP monograph gives a range of 98.5–101.5% for Threonine on a dry basis.
This difference shows why the grade and quality standard should be clearly stated.
FCC compliance may be requested for food-grade products.
Pharmaceutical-grade products may require USP/EP or target pharmacopoeia standard.
For feed-grade products, exact feed additive authorization and documentation on the production organism should be checked for Europe.
STORAGE AND HANDLING OF L-THREONINE
Storage: L-Threonine should be stored in dry, clean, and tightly sealed packaging.
Humidity control: The crystalline amino acid product should not be exposed to unnecessarily high humidity.
Moisture can alter flow characteristics and clumping behavior.
Contamination: Feed, food and pharma qualities should be protected from other raw materials and allergen/drug cross-contamination.
Odor: The product should be kept away from strong-smelling chemicals.
Particle integrity: Excessive mechanical breakage in granular products can create more fine particles and dust.
Warehouse management: FIFO or the appropriate shelf-life tracking system should be used.
Temperature: Normal dry storage conditions are generally suitable, but the exact manufacturer storage temperature should be verified from TDS/SDS.
Packaging: Commercial L-Threonine paper bag can be offered in multi-layer bag or large packaging.
Exact packaging and net weight vary by manufacturer.
Transportation: The dangerous goods classification should be checked against the current SDS of the purchased product.
In food or pharma applications, hygiene and previous load control of the transport vehicle should also be part of the quality system.
L-THREONINE SAFETY INFORMATION
L-Threonine is not a chemical with high volatility under normal use conditions.
PubChem does not show a general GHS hazard classification for L-Threonine.
However, good occupational hygiene should be practiced when handling industrial quantities of powdered products.
Unnecessary inhalation of fine amino acid powder should be avoided.
Intense dust contact with the eyes can cause mechanical discomfort.
Dust control should be carried out during weighing, silo filling or pneumatic transfer.
Food, feed or pharmaceutical use safety and workplace dust exposure should be evaluated separately from each other.
The exact product's SDS document is the main source for storage, personal protective equipment, spill and fire procedures.
WHAT TO CONSIDER WHEN BUYING L-THREONINE?
The first question in L-Threonine procurement should be "what grade?"
Feed-grade, food-grade, supplement-grade and pharmaceutical-grade products should not be evaluated with the same purchasing specification.
The following information should be clarified before purchasing:
Use sector
Animal nutrition
Food
Nutritional support
Pharmaceutical
Laboratory
Desired grade of L-Threonine
Minimum assay
L-isomer purity
Humidity limit
Ash limit
Heavy metal limits
Microbiological criteria
Granular or powder preference
Particle size
Bulk density requirement
Resolution requirement
Fermentation production information
Production organism knowledge
GMO declaration requirement
Food-grade requirement
FCC requirement
USP requirement
EP requirement
Feed authorization information
Preference for origin
Manufacturer preference
Packaging Type
Estimated order quantity
Shelf life
The need for TDS
The need for SDS
The need for COA
GMP/FSSC/ISO/HACCP certificates
Relevant certificate if Halal or Kosher requirement
The price of L-Threonine should not be evaluated solely on the cost per kilogram.
The actual quality and documentation cost of a 98.5% feed-grade product and a higher purity food/pharma product are different.
In feed formulation, the active cost calculation should be made on the assay.
In the use of food or pharma, the cost of the quality system and compliance certificates are also important.
When switching to a new supplier, only the assay should not be compared.
Particle size, bulk density, premix homogeneity, solubility, and production facility consistency should also be evaluated.
L-THREONINE SUPPLY FROM ATAMAN KIMYA
L-Threonine; It is an essential α-amino acid used in animal nutrition, feed premixes, food, nutritional supplements, special nutrition and different technical amino acid applications.
Companies that want to get information about L-Threonine supply from Ataman Kimya can request information about product suitability, current supply conditions, packaging options and price offer by sharing their usage areas and target quality criteria.
The current stock status, manufacturer, origin, feed/food/pharma quality class, purity, physical form, packaging and technical specifications of the product should be confirmed from Ataman Kimya before ordering.
Sharing the following information in the request for quotation makes it easier to evaluate the right L-Threonine product:
Use sector
Final application
Feed-grade, food-grade or pharma-grade
Minimum assay
Desired physical form
Granular or powder preference
Particle size requirement
Bulk density requirement
Microbiological criteria
Heavy metal limits
FCC requirement
USP/EP requirement
Feed authorization requirement
Fermentation/GMO document requirement
Halal or Kosher requirement
Estimated order quantity
Type of packaging requested
Requested technical documents
TDS or COA information of the current product, if applicable
FREQUENTLY ASKED QUESTIONS ABOUT L-THREONINE
What is L-Threonine?
L-Threonine is a natural L-structured and nutritionally essential α-amino acid used in protein synthesis.
What is the Turkish name for L-Threonine?
It is called L-Threonine.
What is the CAS number of L-Threonine?
CAS No is 72-19-5.
What is the molecular formula of L-Threonine?
C₄H₉NO₃.
What is the molecular weight of L-Threonine?
It is approximately 119.12 g/mol.
What is the systematic name for L-Threonine?
(2S,3R)-2-amino-3-hydroxybutanoic acid.
Is L-Threonine an essential amino acid?
It is an essential amino acid in human nutrition and must be supplied in sufficient quantities by ration in many animal nutrition systems.
Is L-Threonine a proteinogenic amino acid?
It is one of the standard amino acids that directly participates in protein synthesis.
Is L-Threonine soluble in water?
PubChem reports a water solubility of 97 g/L at about 25 °C.
What is the solubility for feed-grade L-Threonine?
Evonik's ThreAMINO® white paper gives a value of 90 g/L at approximately 20 °C.
Is L-Threonine soluble in alcohol?
According to FCC and PubChem sources, it is practically insoluble in alcohol.
What is the melting point of L-Threonine?
The FCC states that it melts by degradation at around 256 °C.
In what physical form is L-Threonine?
It is usually white crystal or crystalline powder.
What are the pKa values of L-Threonine?
Values of approximately 2.63 for the carboxyl group and approximately 10.43 for the amino group have been reported.
Does L-Threonine form zwitterion?
The zwitterionic form carrying both positive amino and negative carboxylate groups is dominant in the appropriate pH range.
Why is L-Threonine used in feed?
It is used to supplement the level of threonine in the ration according to the animal's requirement and to balance the amino acid profile.
Why is L-Threonine important in low protein feeds?
When crude protein is reduced, essential amino acid deficiencies can occur. Crystalline L-Threonine helps to supplement the missing threonine in a targeted form.
Is L-Threonine used in pig feed?
Pig nutrition is one of the main uses of feed-grade L-Threonine.
Is L-Threonine used in poultry feed?
It can be widely evaluated in broiler and laying hen rations.
Can L-Threonine be used in pet food?
It can be used in accordance with the nutritional requirement and target legislation. The pet-food/feed authorization status of the exact product should be verified.
Is L-Threonine added to all feeds in a fixed ratio?
The utilization rate is calculated based on the natural amino acid content of the ration and the animal's requirement.
How much is L-Threonine feed-grade purity?
It varies according to commercial grade. A minimum assay of 98.5% is reported for Evonik ThreAMINO® Feed Grade.
Is L-Threonine used in food?
The FDA registers L-Threonine as a nutrient supplement, flavor enhancer and flavoring agent/adjuvant.
What is the FEMA number of L-Threonine?
It is listed in FDA records as FEMA No 4710.
Is L-Threonine available on the FCC?
There is a monograph of L-Threonine in the Food Chemicals Codex.
Is L-Threonine found in USP?
USP has a monograph of Threonine.
What is the range of USP Threonine assay?
The USP monograph preview gives a range of 98.5–101.5% on a dry basis.
Can L-Threonine be used in nutritional supplements?
It can be used according to the appropriate food/supplement-grade quality and the legislation of the target country.
Is L-Threonine a pharmaceutical raw material?
Quality classes with a pharmacopoeia monograph can be found, but not every commercial L-Threonine product is automatically pharmaceutical grade.
Is L-Threonine produced by fermentation?
Commercial L-Threonine can be widely produced by microbial fermentation. The exact microorganism may vary on the basis of manufacturer and product.
Is L-Threonine produced with GMO?
Genetically modified production microorganisms have been used in some authorized feed-grade products, the production system of some products may be different. The exact product document should be checked.
Is L-Threonine the same as D-Threonine?
They are stereoisomers of each other and are not considered biologically identical.
Is L-Threonine the same as L-Serine?
While both are hydroxylated amino acids, their molecular structures and nutritional roles are different.
Are L-Threonine and L-Lysine used for the same purpose?
Both are used in amino acid balancing but are not interchangeable.
Is L-Threonine the same as DL-Methionine?
They are different essential amino acids and their requirements in the ration are calculated separately.
Can L-Threonine be used in amino acid premix?
Due to its high assay, it can be used in concentrated amino acid premixes.
Can L-Threonine be used in liquid premix?
Its water solubility is suitable, but the target concentration and low-temperature crystallization should be tested.
Can L-Threonine do my powder?
Dust may occur during transfer in fine powder grades. Granular products may provide lower dusting in some processes.
What is the bulk density value of L-Threonine?
It depends on the product. Evonik ThreAMINO reports approx. 730 kg/m³ in granular product and approx. 650 kg/m³ in powder form.
What is the most important criterion when buying L-Threonine?
First of all, the right grade should be selected; then the assay, stereoisomer purity, moisture, ash, particle structure and documents suitable for the target application should be evaluated.
What documents should be required for L-Threonine?
TDS, SDS, and COA are essential documents. FCC, USP/EP, feed authorization, GMP, halal, Kosher, and production microorganism documents may also be required depending on the application.
How should L-Threonine be stored?
It should be stored in dry, clean, tightly closed packaging and protected from cross-contamination with moisture.
L-THREONINE – TECHNICAL SUMMARY
L-Threonine, known as L-Threonine, is a natural L-configuration proteinogenic α-amino acid with the formula C₄H₉NO₃. It has CAS No 72-19-5, PubChem CID 6288, and molecular weight of approximately 119.12 g/mol.
The systematic structure of L-Threonine is (2S,3R)-2-amino-3-hydroxybutanoic acid. The molecule carries an amino group, a carboxylic acid, and hydroxyled polar side chain.
Stereochemical identity is important because it has two chiral centers. The natural product used in feed, food, and pharmaceutical applications is the L-Threonine form; D-Threonine or allothreonine should not be considered the same nutritional product.
L-Threonine is white crystal or crystalline powder. PubChem reports a water solubility of 97 g/L at about 25 °C, while Evonik gives 90 g/L at about 20 °C for the feed-type product. FCC specifies melting behavior by degradation at about 256 °C and insolubility in alcohol, ether and chloroform.
Animal nutrition is one of the main uses of L-Threonine. Crystalline L-Threonine can be used to supplement the ration amino acid profile when threonine from natural feed raw materials is insufficient.
In low-protein rations, L-Threonine can enable precise amino acid feeding along with lysine, methionine, and other essential amino acids. Thus, it can help reduce unnecessary high protein utilization and nitrogen excretion.
Evonik's ThreAMINO® Feed Grade is available with a minimum specification of 98.5% L-Threonine, a maximum of 0.5% ash, and a maximum of 0.5% loss on drying. These are manufacturer-specific feed-grade specifications and should not be generalized to all commercial L-Threonine products.
L-Threonine is also a defined raw material in food applications. The FDA lists the product with nutrient supplement, flavor enhancer and flavoring agent/adjuvant functions and provides FEMA No 4710 information.
FCC and USP systems have L-Threonine/Threonine quality monographs. Therefore, when choosing a food-grade or pharmaceutical-grade product, not only the CAS number, but also the relevant monograph and compliance with the quality system should be verified.
L-Threonine can be produced commercially by microbial fermentation. The production microorganism used and GMO status depend on the exact producer and grade; this information should be checked at the time of purchase through TDS, regulatory dossier or manufacturer's declaration.
Companies planning to supply L-Threonine from Ataman Kimya feed, food, supplement or pharmaceutical usage area; It is recommended to confirm the current product and offer conditions by sharing the target assay, physical form, particle properties, legislative standard, packaging quantity and necessary technical documents.
