The storage of L-Alanyl-L-cystine raw materials is affected by various factors, mainly including the following aspects:
I. Temperature
L-Alanyl-L-cystine generally needs to be stored at an appropriate temperature. Excessively high temperatures may cause thermal decomposition, deterioration of the raw materials, or accelerate their chemical reactions, reducing their stability and activity. For example, when the temperature exceeds a certain limit, the intensified thermal motion between molecules may break the peptide bonds and damage its chemical structure.
On the other hand, extremely low temperatures may cause the raw materials to freeze. During the thawing process, the formation and melting of ice crystals may change the physical properties of the raw materials, such as caking and poor solubility. Generally, it is recommended to store L-Alanyl-L-cystine under refrigeration conditions at 2 - 8°C to maintain its stability.
II. Humidity
In a high - humidity environment, L-Alanyl-L-cystine raw materials are prone to absorb moisture from the air and undergo deliquescence. This not only changes the physical form of the raw materials but may also trigger hydrolysis reactions, leading to the destruction of its chemical structure and affecting its quality and performance.
If the humidity is too low, it may cause excessive loss of moisture in the raw materials, making them dry and brittle, which may also affect their usability. Usually, a relative humidity of 40% - 60% is considered a suitable storage environment humidity.
III. Light
High - energy rays such as ultraviolet rays in light may trigger photochemical reactions of L-Alanyl-L-cystine, causing changes in its molecular structure, generating degradation products, and reducing the purity of the raw materials.
Long - term exposure to strong light may also change the color of the raw materials, affecting its appearance quality. Therefore, L-Alanyl-L-cystine raw materials usually need to be stored in a light - protected environment, such as being packaged in brown bottles or opaque containers and placed in a dark place.
IV. Oxygen
Oxygen is oxidizing, and certain groups in L-Alanyl-L-cystine may undergo oxidation reactions with oxygen, thus changing its chemical properties. For example, the sulfhydryl group (-SH) in cystine is easily oxidized to a disulfide bond (-S - S -), which may affect the activity and function of the raw materials in some biological processes.
To reduce the influence of oxygen, methods such as filling with inert gases (e.g., nitrogen) or using sealed packaging are often adopted to isolate the raw materials from oxygen.
V. Storage Time
As the storage time extends, L-Alanyl-L-cystine raw materials will inevitably undergo some physical or chemical changes. Even under suitable storage conditions, factors such as slow chemical reactions and microbial contamination may lead to a gradual decline in its quality.
Due to differences in production processes, impurity contents, and other factors among different batches of raw materials, their shelf - lives may vary. Generally, the effective storage time needs to be determined according to specific product instructions and quality inspection results.
VI. Packaging Materials
The properties of packaging materials have an important impact on the storage of L-Alanyl-L-cystine. If the packaging materials do not have good barrier properties, they cannot effectively block the influence of external factors such as moisture, oxygen, and light.
Some packaging materials may also interact with the raw materials. For example, certain plastic packaging may release some chemical substances that react with the raw materials, affecting its quality. Therefore, it is necessary to select suitable packaging materials, such as glass and high - quality plastics, and ensure good sealing of the packaging.
