What’s the difference between freeze dried and frozen breastmilk?

Both frozen and freeze-dried breast milk aim to preserve the essential nutrients and immunological properties inherent in fresh breast milk. However, the methods differ in their effectiveness and impact on nutritional value:

Nutritional Preservation:

• Freeze-Drying: Freeze-drying breast milk is noted for its ability to largely maintain the nutritional content, antibodies, and immunological factors. A study conducted in Argentina demonstrated that freeze-drying successfully conserved the milk’s nutritional properties including proteins, glucose, triglycerides, and polyphenols over a long term period. Additionally, other peer-reviewed sources confirm that freeze-drying preserves breast milk at peak nutritional quality, keeping vital nutrients, fats, and antibodies intact.
• Freezing: On the other hand, regular freezing starts to decrease the nutritional value of breast milk after 3 months. Over time, freezing impacts the nutritional content of human milk, reducing protein and caloric content. Another study noted a decrease in glucose content after the freezing treatment.

 Shelf Life:

• Freeze-Drying: Freeze-dried breast milk can be stored for up to 3 years without significant loss in nutritional value, which is a substantial advantage in terms of shelf life .
• Freezing: Frozen breast milk’s nutritional value begins to decrease after 3 months, and it may go to waste after 6 months.

Ease of Preservation:

• Freeze-Drying: The process of freeze-drying, although requiring specific equipment, is noted for its ability to improve bank functioning by protecting nutritional properties with easy maintenance over a longer period .
• Freezing: Freezing is a simpler method but does not offer the long-term preservation benefits that freeze-drying does. 

Vitamin Preservation:

• Freeze-Drying: The literature suggests that freeze-drying can better preserve certain vitamins in breast milk. Although specific data might be limited, it’s generally understood that the gentle process of freeze-drying helps in retaining sensitive nutrients.
• Freezing: Freezing, especially for extended periods, can lead to a gradual loss of some vitamins. For instance, the levels of Vitamin C, a water-soluble vitamin, can decrease over time in frozen storage. 

Enzyme Activity:

• Freeze-Drying: Freeze-drying may better preserve the enzyme activity in breast milk, which is crucial for digestibility and absorption.
• Freezing: Freezing can potentially inactivate some enzymes, although the extent of this effect might vary.

Immune Factors:

• Freeze-Drying: A study found that most immunoglobulins in breast milk stayed stable when it was freeze-dried. Immunoglobulins are crucial for building the infant’s immune system .
• Freezing: Freezing may also preserve immunological factors to some extent, but the duration of storage and the temperature may affect their stability.

Microbial Growth:

• Freeze-Drying: The process of freeze-drying reduces the moisture content significantly, in turn inhibiting microbial growth and making the milk safe for longer-term storage .
• Freezing: While freezing also inhibits microbial growth, once thawed, the milk should be consumed relatively quickly to prevent microbial contamination.

Convenience and Usability:

• Freeze-Drying: Freeze-dried breast milk can be easily rehydrated and used, making it a convenient choice for busy families and working parents. Plus, the long shelf life of freeze-dried breast milk offers a hassle-free storage solution.
• Freezing: Frozen breast milk requires thawing, which needs to be done safely to prevent bacterial growth. It’s also bulkier to store and transport compared to freeze-dried milk.