1. Formula design of protective agent

Add freeze-drying protectants (such as lactose, glycerol, trehalose, or skim milk powder) to reduce ice crystal damage and maintain cell membrane integrity. For example, xylan can enhance the proliferation effect of bacterial strains, while glycerol can reduce metabolic damage.

Optimize the concentration of protective agents based on the characteristics of the bacterial strain (usually the quality of the bacterial solution)5-20%）And determine the optimal ratio through pre experiments.

1Full process control of freeze-drying technology

1. Preprocessing and disk loading After fermentation is completed, it is centrifuged（4000-6000 rpm）Filter and remove impurities, concentrate the bacterial solution to a water content15-20%To avoid the formation of excessive ice crystals during freeze-drying. Divide the bacterial solution evenly into freeze-drying trays or penicillin bottles, with the thickness controlled within3-5 mmEnsure uniform drying.

2. Optimization of freeze-drying process parameters Pre freezing stage: rapidly cool down to-40Below ℃（5-10Minutes), allowing water to form small ice crystals and reducing cellular structural damage. One drying: Vacuum degree ≤5 PaThe temperature of the board layer gradually rises-20℃ to0℃, sublimation time is adjusted according to the thickness of the bacterial solution (usually24-48Hour). Analysis of drying: Heat up to25-30℃, residual moisture decreases to1%Below, restore bacterial activity.

3. Automation and intelligent equipment

Adopting a fully automatic microsphere molding machine, fully automatic freeze-drying machine, and fully automatic microsphere packaging assembly line.

equipCIP/SIPOnline cleaning and sterilization system to ensure a sterile production environment (e.gISO 14644-1 Class 8Standard).
3、 Quality inspection and packaging plan

1. Key quality indicators（CQI）

Live bacteria count: must reach ≥10^9 CFU/g(such as capsules) or ≥10^10 CFU/g(such as powder), detected by plate counting method or flow cytometry. Water activity: controlled within0.3To prevent microbial resurrection or oxidation. Hydrability:30Solubility within seconds ≥95%Ensure the convenience of using terminal products.

2. Packaging and Storage Using aluminum-plastic composite film or nitrogen displacement packaging to block the penetration of oxygen and moisture, extending the shelf life to2-3Year. The recommended storage temperature is2-8℃, avoid high temperature or light that may cause a decrease in activity.