Chemical Properties
Lysine appears as white crystals or crystalline powder, is odorless, and has a sweet taste. Because pure lysine easily absorbs moisture and agglomerates, it is often prepared as its hydrochloride salt for easier separation, purification, and application. It is generally stable (at relative humidity below 60%), but will absorb moisture and agglomerate above 60%, forming a dihydrate. It is readily soluble in water (40%, 35°C) and virtually insoluble in ethanol and ether. It decomposes when heated with reducing sugars such as glucose, producing an appetizing bready aroma. Its mp is 263-264°C, its isoelectric point is 10.56, [α]25D+13.5° (H2O), and [α]25D+26.0 (5 mol/L HCl). Lysine is one of the essential amino acids for the human body. Nutritionists classify it as the "first deficient amino acid." It plays a vital role in maintaining ammonia balance in the human body. If the human body lacks lysine, it will cause protein metabolism disorders. During children's development period, illness recovery period and pregnancy and lactation period, the nutritional requirements for lysine are higher.
