The invention discloses a controlled-release antibacterial edible
composite film and a preparation method thereof. Soy isolate
protein serves as a main substrate, glycerin,
pectin,
nisin,
sodium lactate and the like are added according to a specific proportion, so that
antibacterial activity and the mechanical performance of the film are improved, and
coating is performed for three times by the aid of
ultrasound-assisted technology to prepare a controlled-release edible
antibacterial protein composite film. The
antibacterial activity of the
composite film can be effectively improved by
nisin-
sodium lactate bacteriostatic agents, and microbe development is prevented. Release of the bacteriostatic agents can be effectively controlled by a multilayer
film structure prepared by controlled-release technology, and the
antibacterial activity of the film is greatly enhanced. The antibacterial activity of the antibacterial composite film slightly changes within two months during storage period, the mechanical performance also slightly changes, the
diameter of an antibacterial ring is decreased by 10-15%, tensile strength is reduced by 3-9%, water permeability is enhanced by 2-7%,
oxygen permeability is enhanced by 4-5.5%, the color of the film is transparent and does not remarkably change, and the effective period of
food quality is prolonged. The composite film is simple to operate, stable and reliable in product quality and suitable for industrial production.