Development of a pH indicator composed of high moisture-absorbing materials for real-time monitoring of chicken breast freshness.

A colorimetric bromocresol purple dye-based pH-responsive indicator was developed to monitor the quality of chicken breast meat by direct surface contact. To prevent direct contact of the dye with the chicken breast and to improve its color change sensitivity, it was immobilized with polyvinyl alcohol and a high-absorbance material. The color of the pH indicator changes from yellow to blue and finally purple to indicate spoilage, which can be easily detected by the naked eye. The asprepared pH indicator exhibited good response to pH changes on the surface of chicken breast meat, and no migration of the dye from the indicator onto the surface of the chicken was observed. This pH indicator exhibits excellent feasibility for real-time, direct-contact monitoring of the freshness and quality of various foods.