A colorimetric film, its preparation method and application

Abstract

This invention belongs to the field of thin film processing technology, and relates to a colorimetric membrane, its preparation method, and its application. The colorimetric membrane prepared according to this invention comprises, by mass parts, 2.3-2.7 parts sodium alginate, 1.1-1.4 parts rice protein powder, 1.1-1.4 parts gelatin, 1.1-1.4 parts glycerol, 0.2-0.3 parts polydimethylsiloxane, and 0.15-0.25 parts anthocyanins; it may also include alizarin and phenolic acids. The colorimetric membrane of this invention has a wide pH response color gamut and color intensity, and good mechanical properties. The total color difference of the colorimetric membrane of this invention can reach up to 54.19, making the response of the colorimetric membrane material to the alkaline environment during food spoilage more intuitive and discernible. This invention uses specific types of phenolic acids, which significantly improves color stability while maintaining the wide color gamut response of the composite membrane; this stability and enhanced color development provide a guarantee for the long-term reliable application of intelligent packaging in the circulation and storage stages.

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