The workflow of freeze-dried cordyceps:

1. Preparation of Cordyceps sinensis samples: Select fresh Cordyceps sinensis mycelium or intact Cordyceps sinensis fruiting bodies as samples. Ensure the quality and purity of the sample.

2. Preprocessing samples: Preprocess cordyceps samples as needed. This may include steps such as cleaning, disinfection, cutting, or separation for better freeze-drying.

3. Sample installation: Distribute the Cordyceps sinensis sample evenly in the tray or container of the freeze-drying machine. Ensure that the sample is not too dense to allow for circulation of air and cooling.

4. Setting parameters: Based on the characteristics of Cordyceps sinensis and the required freeze-drying conditions, set the temperature, vacuum degree, and time parameters of the freeze-drying machine. Usually, the temperature of the freeze-drying machine is set at a lower temperature to effectively freeze the sample.

5. Start the freeze-drying process: Start the freeze-drying machine to start working. The freeze-drying process gradually lowers the temperature and establishes a vacuum environment to convert the moisture in the sample into ice crystals, which are then directly transformed into a gaseous state through sublimation, thereby achieving freeze-drying.

6. Monitoring the freeze-drying process: During the entire freeze-drying process, closely monitor the parameters of the freeze-drying machine, such as temperature, vacuum degree, and time. Ensure the stability and smooth progress of the freeze-drying process.

7. Complete the freeze-drying process: Once the freeze-drying process is completed, turn off the freeze-drying machine and wait for the sample to reach room temperature. At this point, the Cordyceps sinensis sample has been freeze-dried and can be taken out for subsequent processing and storage.

The freeze-drying of grass has the advantages of retaining more active ingredients, maintaining intact morphology and structure, extending shelf life, and improving solubility and stability compared to drying. The details are as follows:

1. Preserving active ingredients: Freeze drying is a low-temperature drying method that can remove moisture while maintaining the active ingredients of Cordyceps sinensis samples. During the freeze-drying process, the bioactive substances in Cordyceps sinensis, such as polysaccharides, triterpenoids, peptides, etc., were effectively retained through rapid freezing and vacuum dehydration. In contrast, the high temperature during the drying process may cause the degradation and loss of some thermosensitive components.

2. Maintain intact morphology and structure: During the freeze-drying process, the cordyceps sinensis sample is quickly frozen at low temperature and then dehydrated in a vacuum environment, which helps to maintain the morphology and cellular structure of the cordyceps sinensis sample. After freeze-drying, the appearance of Cordyceps sinensis is intact, without obvious deformation, shrinkage, or color changes, maintaining its natural form and characteristics. During the drying process, due to the effect of high temperature, the cordyceps samples may undergo deformation, shrinkage, and color changes, resulting in a decrease in appearance quality.

3. Extension of shelf life: During the freeze-drying process, the moisture in Cordyceps is completely removed, effectively reducing the conditions for microbial growth, thereby extending the shelf life of Cordyceps. The freeze-dried cordyceps samples are relatively dry and less susceptible to contamination and growth by microorganisms such as molds and bacteria. The dried cordyceps, due to its high moisture content, is prone to the growth of mold and bacteria, resulting in decreased quality and shortened shelf life.

4. Improve solubility and stability: During the freeze-drying process, the soluble components in Cordyceps sinensis are retained, making it more soluble and stable. The freeze-dried Cordyceps sinensis sample is relatively pure and free of water, making it easier to dissolve in solvents for further extraction and preparation. In addition, the low-temperature environment during the freeze-drying process helps to maintain the stability of some components in Cordyceps, preventing their degradation and denaturation.