The stability of L-Alanyl-L-Cystine in nutritional supplements can be enhanced by optimizing the formulation, controlling the processing conditions, and improving storage conditions. Below are specific methods:
1. Optimizing the Nutritional Supplement Formulation
Adjusting pH Levels: The stability of L-Alanyl-L-cystine varies under different pH conditions. It is generally more stable in a weakly acidic to neutral environment with a pH range of 5-7. Adding pH regulators such as citric acid and potassium dihydrogen phosphate can help adjust the pH of the nutritional supplement to an appropriate range, reducing its hydrolysis or degradation.
Adding Chelating Agents: Metal ions such as iron and copper can catalyze the oxidation or other reactions of L-Alanyl-L-Cystine, reducing its stability. The addition of chelating agents like ethylenediaminetetraacetic acid (EDTA) and its salts can form stable chelates with metal ions, minimizing their impact on L-Alanyl-L-Cystine.
Incorporating Antioxidants: The thiol (-SH) group in L-Alanyl-L-Cystine is prone to oxidation. Adding antioxidants can prevent its oxidation. Common antioxidants include ascorbic acid (vitamin C) and α-tocopherol (vitamin E), which preferentially react with oxygen and other oxidants to protect L-Alanyl-L-Cystine. The recommended dosage of antioxidants is typically 0.1%-0.5% of the total nutritional supplement weight.
Selecting Suitable Excipients: The properties of excipients can affect the stability of L-Alanyl-L-Cystine. For example, using lactose, mannitol, and other stable, low-hygroscopic substances as excipients helps maintain the physical and chemical stability of the nutritional supplement, preventing deterioration due to moisture absorption.
2. Controlling the Processing Conditions
Temperature Control: High temperatures can accelerate the decomposition of L-Alanyl-L-Cystine. During the production and processing of nutritional supplements, excessive heat should be avoided. It is generally recommended to keep processing temperatures below 30°C. Using low-temperature drying or freeze-drying techniques can effectively reduce the impact of high temperatures on stability.
Humidity Control: High humidity environments can cause L-Alanyl-L-Cystine in nutritional supplements to absorb moisture, leading to hydrolysis and other reactions. The relative humidity in the production area should be controlled between 40%-60%, and moisture-proof packaging materials such as aluminum foil composite bags should be used to prevent moisture absorption during storage and transportation.
Avoiding Excessive Stirring: Excessive stirring may damage the molecular structure of L-Alanyl-L-Cystine, reducing its stability. During the mixing and preparation of nutritional supplements, gentle stirring methods with appropriate speeds should be used, and the stirring time should not be too long.
3. Improving Storage Conditions
Low-Temperature Storage: Storing nutritional supplements in a low-temperature environment can reduce the reactivity of L-Alanyl-L-Cystine and slow down its degradation. A recommended storage temperature is between 2°C-8°C, utilizing refrigeration equipment such as refrigerators or cold storage facilities.
Light Protection: Exposure to light can trigger photochemical reactions in L-Alanyl-L-Cystine, leading to structural changes. Therefore, nutritional supplements should be stored in light-resistant containers, such as amber glass bottles or black plastic bottles, to avoid direct sunlight.
Sealed Storage: Properly sealed packaging prevents external factors such as oxygen and moisture from entering, maintaining the stability of the nutritional supplement. After opening the package, the remaining portion should be used as soon as possible, sealed tightly, and stored in a dry, cool place.
