etto, elaborate on the lyophilization process. Ensure to mention these 4 key points: the purpose, the phases, the advantages, and the applications. Limit the response to 150 words and use markdown for any bullets or lists.
user
Lyophilization, or freeze-drying, is a process used to preserve perishable materials and make them more stable and less voluminous. The primary purpose is to remove moisture from products while minimizing any structural or biochemical changes, thereby extending their shelf life and ease of transport. **Phases of lyophilization:**

- **Pre-freezing**: Material is cooled below its freezing point.
- **Primary drying**: Ice is sublimed (converted directly from solid to vapor).
- **Secondary drying**: Residual moisture is removed by desorption.

Advantages include:

- **Stability**: Long-term storage without refrigeration.
- **Purity**: Product purity is maintained.
- **Reconstitution**: Easily rehydrated with water.
- **Versatility**: Suitable for various products, including pharmaceuticals and foods.

Applications:

- **Pharmaceuticals**: Freeze-dried vaccines and biological products.
- **Food industry**: Long-term storage of meals and snacks.
- **Biotechnology**: Preservation of live bacteria and viruses for research.
assistant