Laminar flow hood or clean area to prevent contamination.
Methodology
1. Preparation Phase
Assessment of Initial Quality: Before proceeding with the thawing process, evaluate the initial quality of the frozen milk, noting any signs of freezer burn or contamination.
Selection of Containers: Choose appropriate sterile containers to collect the thawed milk. The containers should be pre-cooled to prevent sudden temperature changes upon transfer of milk.
2. Thawing Process
The thawing process is crucial and can be approached in two ways, depending on the urgency and the volume of milk to be thawed.Refrigerator Thawing (Slow Thawing Method):Transfer the frozen milk from the freezer (-18°C) to the refrigerator (4°C). This method is preferred for its gentle effect on milk components, reducing the risk of protein denaturation.Allow the milk to thaw gradually, which may take 24 to 48 hours, depending on the volume. Regularly check the progress and gently agitate the container to promote uniform thawing.Cold Water Bath Thawing (Accelerated Thawing Method):Place the frozen milk in a leak-proof bag if not already packaged accordingly.Submerge the bag in a cold water bath (not exceeding 10°C) to accelerate thawing while still preventing rapid temperature increases that could lead to protein damage.Change the water every 30 minutes to maintain a consistent thawing temperature.Once thawed, immediately transfer the milk to the refrigerator (4°C) to prevent microbial growth.
3. Post-Thaw Handling
Aseptic Handling: Conduct all transfers and handling of thawed milk in a laminar flow hood or clean area to prevent contamination.Quality Assessment: After thawing, assess the milk for any changes in physical appearance, smell, or consistency that may indicate degradation or contamination.Preparation for Lactoferrin Extraction: Proceed with lactoferrin extraction as soon as possible after thawing to minimize the time for potential microbial growth and further degradation of milk components.