The invention discloses a microbial freeze-
drying embedding method based on a pH-triggered
phase change mechanism. The method comprises the following steps: step 1, preparing a zein solution: dissolving zein into a
sodium hydroxide solution; step 2, preparing a bacterial suspension: taking fresh excrement of a
healthy donor as a
raw material, diluting with normal
saline, uniformly stirring and mixing, and filtering with a multi-stage filter screen to obtain the bacterial suspension; 3, preparing an intestinal
flora freeze-
drying protective agent: dissolving
lactose,
maltotriose,
mannitol,
trehalose and
antifreeze protein in normal
saline according to a ratio, and sterilizing for later use; step 4, constructing a composite
system: centrifugally washing the bacterial suspension, adding a freeze-
drying protective agent, uniformly mixing in a vortex manner, adding a zein solution in proportion, and sufficiently and uniformly mixing; and step 5, freeze-drying treatment: performing vacuum freeze-drying on the composite
system to form a compact hydrophobic protective layer, thereby obtaining the freeze-dried intestinal
flora powder. According to the invention, the pH response characteristic of the
protein is coupled with a freeze-drying process, so that efficient embedding protection of intestinal
flora is realized.