Convenient and fast poultry, fish and shrimp freshness intelligent indicating film based on betacyanin and preparation method thereof

The invention discloses a convenient and fast poultry, fish and shrimp freshness intelligent indicating film based on betacyanin and a preparation method thereof, and belongs to the field of food engineering. The preparation method of the intelligent indicating film comprises the following steps that (1) film-preparing slurry containing 2-60 mg/kg of betacyanin is prepared, and the pH value is adjusted to 7.2-8.0; (2) the film-preparing slurry is sheared and homogenized to obtain film-forming slurry; (3) the film-forming slurry coats or is poured to cast a film blank; and (4) the film blank isdried, and subjected to film uncovering treatment to obtain the intelligent indicating film containing the betacyanin. The betacyanin in the intelligent indicating film responds to spoilage of freshpoultry, fishes and shrimps to generate biogenic amine, and the color of the intelligent indicating film is gradually changed from red/pink to yellow or even colorless; the reacted intelligent indicating film is compared with