The application of natural food colorants as indicator substances in intelligent biodegradable packaging materials

This paper presents innovative packaging materials made of environmentally friendly biodegradable polymers (polylactide and polyhydroxybutyrate) with the addition of natural colorants commonly used in the food industry. Colorants fulfilled the role of indicator, changing colour under the influence of external factors, and gave the materials the characteristics of intelligent packaging, where colour changes indicated the life time of the materials. The paper gives the mechanical and thermal properties of the materials obtained, and describes changes in the colour of the samples under the influence of thermooxidation, UV and weathering, as well as the biodegradability of the materials. The packaging materials presented are in line with current trends in the packaging market and legal requirements. The samples, in addition to the basic functions of packaging materials, are pro-ecological and fully biodegradable new generation materials.