The invention discloses a preparation method of a nested
sodium alginate /
synbiotics edible fresh-keeping film, and belongs to the technical field of
functional food packaging materials. Mixing probiotics with
xylooligosaccharide,
glycerol,
sodium alginate and the like to prepare an inner-layer solution, and performing
vacuum drying to obtain an inner-layer functional film; a natural
thickening agent and
sodium alginate are compounded to prepare an outer layer
matrix solution, a semi-
solid supporting bottom layer is prepared firstly, then an inner layer film is flatly laid, an outer layer solution is poured for the second time, and the nested film is obtained after
drying. A hydrophobic
physical barrier is constructed on the outer layer, the
water contact angle is increased to 108.03 degrees, the
ultraviolet light
transmittance is reduced to 25.58%, and the permeability of
oxygen is remarkably limited. And the
viable count of the probiotics stored for 30 days reaches 7.36 Log CFU / g, which is obviously superior to that of a single-layer film. The quality of the strawberries in the storage period is remarkably improved when the strawberries are used as outer packages. Through collaborative innovation of structural design and a co-embedding
system, the film is excellent in barrier property,
probiotic activity maintenance and fresh-keeping effect, and is suitable for
open type food long-acting fresh-keeping packaging.