Newly Developed Starch-Based Hydroxyethyl Cellulose Film with Wide Spectrum of pH-Colour Indicator

Active packaging is a promising form of modern food packaging with great potential; economically, environmentally and generally, as it gives a lot of health benefits. Active and smart packaging is made by incorporating suitable colour indicators into food package matrices and applying a bio switch concept to inhibit the spoilage and the pathogenic microorganisms. The main objective of this study are to evaluate starch-based hydroxyethyl cellulose (HEC) the best formulation of methyl red and bromothymol blue that can react with wide pH ranges and the effect of the smart film indicator incorporated with methyl red and bromothymol blue. A solution casting method was used in the film preparation and colour indicators were incorporated before casting. The ratio of 50:50 methyl red and bromothymol blue showed the best formulation which can react with a wide range of pH buffer 1 to 13 compared to ratio 20:80 and 80:20 of methyl red and bromothymol blue. The ratio of 50:50 methyl red and bromothymol blue were then selected to be incorporated into the film to see the effectiveness of the indicator film in order to detect the changes of pH.