Overview
Threonine is one of the 20 standard amino acids and is classified as an essential amino acid, meaning it cannot be synthesized by the human body and must be obtained through diet or supplementation. It was first isolated from oat proteins in 1935 by William Cumming Rose. As a polar, uncharged amino acid with a hydroxyl group, threonine plays critical roles in protein structure and function. In industrial terms, threonine is primarily produced through microbial fermentation using genetically modified strains of Escherichia coli or Corynebacterium glutamicum. The global market for threonine is driven by its extensive use in animal nutrition, particularly in poultry and swine feed formulations where it helps optimize protein utilization.
Physical and Chemical Properties
Threonine exists as white, odorless crystals with a slightly sweet taste. It is optically active, with the L-isomer being the biologically active form. The compound shows good stability under normal storage conditions but may degrade at temperatures above its melting point. Chemically, threonine features both a carboxyl group and an amino group characteristic of amino acids, along with a secondary alcohol group that makes it a hydroxyl-containing amino acid. This structure enables participation in hydrogen bonding and post-translational modifications like glycosylation in proteins. Its isoelectric point is at pH 5.64, and it shows zwitterionic properties in aqueous solutions.
Main Applications
The largest application of threonine is in animal feed, where it accounts for approximately 70% of global consumption. As the second-limiting amino acid in poultry diets (after methionine), it's crucial for efficient feed conversion and growth performance. In swine nutrition, threonine supports gut health and immune function. Pharmaceutical applications include use in parenteral nutrition solutions and as a component in amino acid infusion therapies. The food industry utilizes threonine in fortification of cereal products and as a flavor enhancer. Emerging applications include use in cosmetic formulations for skin-conditioning properties and in biotechnological processes as a fermentation nutrient.
Safety and Storage
Threonine is generally considered safe with low toxicity (LD50 >5000 mg/kg in rats). Proper handling involves standard precautions for fine powders - use local exhaust ventilation to control dust formation and wear protective gloves/eyewear if prolonged contact is expected. For long-term storage, keep containers tightly sealed in original packaging at room temperature (15-25°C) with relative humidity below 65%. Avoid exposure to direct sunlight and oxidizing agents. Under proper conditions, the shelf life typically exceeds 3 years. Bulk quantities should be stored on pallets in dry warehouses with adequate ventilation.
B2B Procurement Guide
When sourcing threonine commercially, buyers should specify required grade (feed, food, or pharmaceutical), purity level, and packaging preferences (25kg bags, big bags, or bulk containers). Key quality parameters include assay (≥98.5%), heavy metal content (<10 ppm), and optical purity (L-form content ≥99%). Major global producers are concentrated in China, Europe, and North America. Price trends correlate with raw material (corn) costs and energy prices. For large-volume purchases (multiple metric tons), consider negotiating long-term contracts with price adjustment clauses. Verify supplier certifications including ISO, FAMI-QS for feed applications, or relevant GMP standards for pharmaceutical use.